INVENTORS 


UNIVERSITY  OF  CALIFORNIA  LIBRARY 


Copyright  by  Park  &  Co.,  Brantford,  Ontario. 

PROFESSOR  ALEXANDER  GRAHAM  BELL. 


Inventors  at  Work 

With  Chapters  on  Discovery 


By  George  lies 

Author  of  "  Flame,  Electricity  and  the  Camcn 


Copiously  Illustrated 


or  THE 
UNIVERSITY 


New  York 
Doubleday,  Page  &  Company 

1906 


Copyright,  1906,  by 
GEORGE  ILES 

Published  October,  1906 

All  rights  reserved,  including  that 
of  translation  into  foreign  Ian- 
guages,  including  the  Scandinavian 


iv 


TO  MY  FRIEND 

JOSEPHUS  NELSON  LARNED 

OF  BUFFALO,  NEW  YORK 


CONTENTS 

PACT 

LIST  OF  ILLUSTRATIONS xiii 

ACKNOWLEDGMENTS xxi 

CHAPTER 

I.    INTRODUCTORY  I 

II.    FORM 

Form  as  important  as  substance.  Why  a  joist  is  stiffer 
than  a  plank.  The  girder  is  developed  from  a  joist.  Rail- 
road rails  are  girders  of  great  efficiency  as  designed  and 
tested  by  Mr.  P.  H.  Dudley 5 

III.  FORM  CONTINUED.    BRIDGES 

Roofs  and  small  bridges  may  be  built  much  alike.  The 
queen-post  truss,  adapted  for  bridges  in  the  sixteenth  cen- 
tury, neglected  for  two  hundred  years  and  more.  A  truss 
replaces  the  Victoria  Tubular  Bridge.  Cantilever  spans  at 
Niagara  and  Quebec.  Suspension  bridges  at  New  York. 
The  bowstring  design  is  an  arch  disguised.  Why  bridges 
are  built  with  a  slight  upward  curve.  How  bridges  are 
fastened  together  in  America  and  in  England 18 

IV.  FORM     CONTINUED.      LIGHTNESS,     EASE     IN 

MOTION 

Why  supports  are  made  hollow.  Advantages  of  the  arch 
in  buildings,  bridges  and  dams.  Tubes  in  manifold  new 
services.  Wheels  more  important  than  ever.  Angles  give 
way  to  curves 39 

V.    FORM   CONTINUED.     SHIPS 

Ships  have  their  resistances  separately  studied.  This  leads 
•to  improvements  of  form  either  for  speed  or  for  carrying 
capacity.  Experiments  with  models  in  basins.  The  Viking 
ship,  a  thousand  years  old,  of  admirable  design.  Clipper 
ships  and  modern  steamers.  Judgment  in  design  .  .  .  .  52 
vii 


viii  CONTENTS 

VI.  FORM  CONTINUED.  RESISTANCE  LESSENED 
Shapes  to  lessen  resistance  to  motion.  Shot  formed  to  move 
swiftly  through  the  air.  Railroad  trains  and  automobiles 
of  somewhat  similar  shape.  Toothed  wheels,  conveyors, 
propellers  and  turbines  all  so  curved  as  to  move  with  ut- 
most freedom 65 

VII.    FORM  CONTINUED.     ECONOMY  OF  LIGHT  AND 

HEAT 

Light  economized  by  rightly-shaped  glass.  Heat  saved  by 
well-designed  conveyors  and  radiators.  Why  rough  glass 
may  be  better  than  smooth.  Light  is  directed  in  useful 
paths  by  prisms.  The  magic  of  total  reflection  is  turned  to 
account.  Holophane  Globes.  Prisms  in  binocular  glasses. 
Lens  grinding.  Radiation  of  heat  promoted  or  prevented 
at  will 72 

VIII.  FORM  CONTINUED.  TOOLS  AND  IMPLEMENTS 
Tools  and  implements  shaped  for  efficiency.  Edge  tools  old 
and  new.  Cutting  a  ring  is  easier  than  cutting  away  a 
whole  circle.  Lathes,  planers,  shapers,  and  milling  ma- 
chines far  out-speed  the  hand.  Abrasive  wheels  and  presses 
supersede  old  methods.  Use  creates  beauty.  Convenience 
in  use.  Ingenuity  spurred  by  poverty  in  resources  ...  89 

IX.    FORM  CONTINUED.     ABORIGINAL  ART 

Form  in  aboriginal  art,  as  affected  by  materials.  Old  forms 
persist  in  new  materials.  Nature's  gifts  first  used  as  given, 
then  modified  and  copied.  Rigid  materials  mean  stiff  pat- 
terns. New  materials  have  not  yet  had  their  full  effect  on 
modern  design 108 

X.     SIZE 

Heavenly  bodies  large  and  small.  The  earth  as  sculptured 
a  little  at  a  time.  The  farmer  as  a  divider.  Dust  and 
its  dangers.  Models  may  mislead.  Big  structures  econom- 
ical. Smallness  of  atoms.  Advantages  thereof.  Dust  re- 
pelled by  light .  120 

XI.     PROPERTIES 

Food  nourishes.  Weapons  and  tools  are  strong  and  lasting. 
Clothing  adorns  and  protects.  Shelter  must  be  duraHe. 
Properties  modified  by  art.  High  utility  of  the  bamboo. 
Basketry  finds  much  to  use.  Aluminium,  how  produced  and 
used.  Qualities  long  unwelcome  or  worthless  are  now  gain- 
ful. Properties  created  at  need 135 


CONTENTS 


IX 


XIT.    PROPERTIES  CONTINUED 

Producing  more  and  better  light  from  both  gas  and  elec- 
tricity. The  Drummond  light.  The  Welsbach  mantle. 
Many  rivals  of  carbon  filaments  and  pencils.  Flaming  arcs. 
Tubes  of  mercury  vapor 154 

XIII.  PROPERTIES  CONTINUED 

Steel:  its  new  varieties  are  virtually  new  metals,  strong, 
tough,  and  heat  resisting  in  degrees  priceless  to  the  arts. 
Minute  admixtures  in  other  alloys  are  most  potent  .  .  .163 

XIV.  PROPERTIES  CONTINUED 

Glass  of  new  and  most  useful  qualities.  Metals  plastic  un- 
der pressure.  Non-conductors  of  heat.  Norwegian  cooking 
box.  Aladdin  oven.  Matter  seems  to  remember.  Feeble 
influences  become  strong  in  time 180 

XV.    PROPERTIES  CONTINUED.    RADIO-ACTIVITY 

Properties  most  evident  are  studied  first.  Then  those  hid- 
den from  cursory  view.  Radio-activity  revealed  by  the  elec- 
trician. A  property  which  may  be  universal,  and  of  the 
highest  import.  Its  study  brings  us  near  to  ultimate  ex- 
planations. Faraday's  prophetic  views 197 

XVI.    MEASUREMENT 

Methods  beginning  in  rule-of-thumb  proceed  to  the  utmost 
refinement.  Standards  old  and  new.  The  foot  and  cubit. 
The  metric  system.  Refined  measurement  as  a  means  of 
discovery.  The  interferometer  measures  .^1^  inch.  A 
light-wave  as  an  unvarying  unit  of  length 208 

XVII.    MEASUREMENT  CONTINUED 

Weight,  Time,  Heat,  Light,  Electricity,  measured  with  new 
precision.  Exact  measurement  means  interchangeable  de- 
signs, and  points  the  way  to  utmost  economies.  The  Bureau 
of  Standards  at  Washington.  Measurement  in  expert  plan- 
ning and  reform 219 

XVIII.    NATURE  AS  TEACHER 

Forces  take  paths  of  least  resistance.  Accessibility  decides 
where  cities  shall  arise.  Plants  display  engineering  prin- 
ciples in  structure.  Lessons  from  the  human  heart,  eyes, 
bones,  muscles,  and  nerves.  What  nature  has  done,  art  may 
imitate, — in  the  separation  of  oxygen  from  air,  in  flight,  in 
producing  light,  in  converting  heat  into  work.  Lessons 
from  lower  animals.  A  hammer-using  wasp 245 


x  CONTENTS 

XIX.    QUALIFICATIONS    OF    INVENTORS     AND    DISCOV- 
ERERS 

Knowledge  as  sought  by  disinterested  inquirers.  A  plente- 
ous harvest  with  few  reapers.  Germany  leads  in  original 
research.  The  Carnegie  Institution  at  Washington  .  .  .  267 

XX.    OBSERVATION 

What  to  look  for.  The  eye  may  not  see  what  it  does  not 
expect  to  see.  Lenses  reveal  worlds  great  and  small  other- 
wise unseen.  Observers  of  the  heavens  and  of  seashore  life. 
Collections  aid  discovery.  Happy  accidents  applied  to  profit. 
Popular  beliefs  may  be  based  on  truth.  An  engineer  taught 
by  a  bank  swallow 279 

XXI.    EXPERIMENT 

Newton,  Watt,  Ericsson,  Rowland,  as  boys  were  construc- 
tive. The  passion  for  making  new  things.  Aid  from  imag- 
ination and  trained  dexterity.  Edison  tells  how  the  phono- 
graph was  born.  Telephonic  messages  recorded.  Hand- 
writing transmitted  by  electricity.  How  machines  imitate 
hands.  Originality  in  attack 299 

XXII.    AUTOMATICITY  AND  INITIATION 

Self-acting  devices  abridge  labor.  Trigger  effects  in  the 
laboratory,  the  studio  and  the  workshop.  Automatic  tele- 
phones. Equilibrium  of  the  atmosphere  may  be  easily  up- 
set   329 

XXIII.  SIMPLIFICATION 

Simplicity  always  desirable,  except  when  it  costs  too  dear. 
Taking  direct  instead  of  roundabout  paths.  Omissions  may 
be  gainful.  Classification  and  signaling  simpler  than  ever 
before 340 

XXIV.  THEORIES  HOW  REACHED  AND  USED 
Educated  guessing.     Weaving  power.     Imagination  indis- 
pensable.    The  proving  process.     Theory  gainfully  directs 
both  observation  and  experiment.     Tyndall's  views.     Dis- 
cursiveness of  Thomas  Young 355 

XXV.    THEORIZING  CONTINUED 

Analogies  have  value.  Many  principles  may  be  reversed 
with  profit.  The  contrary  of  an  old  method  may  be  gain- 
ful. Judgment  gives  place  to  measurement,  and  then  passes 
to  new  fields 366 


CONTENTS  xi 

XXVI.    NEWTON,  FARADAY  AND  BELL  AT  WORK 

Newton,  the  supreme  generalizer.  Faraday,  the  master  of 
experiment.  Bell,  the  inventor  of  the  telephone,  transmits 
«oeech  by  a  beam  of  light 387 


XXVII.    BESSEMER,  CREATOR  OF  CHEAP  STEEL.    NOBEL, 

INVENTOR  OF  NEW  EXPLOSIVES 
Bessemer  a  man  of  golden  ignorances.  His  boldness  and 
versatility.  The  story  of  his  steel  process  told  by  himself. 
Nobel's  heroic  courage  in  failure  and  adversity.  His  tri- 
umph at  last.  Turns  an  accidental  hint  to  great  profit.  In- 
ventors to-day  organized  for  attacks  of  new  breadth  and 
audacity  401 


XXVIII.    COMPRESSED  AIR 

An  aid  to  the  miner,  quarryman  and  sculptor.  An  actu- 
ator for  pumps.  Engraves  glass  and  cleans  castings.  Dust 
and  dirt  removed  by  air  exhaustion.  Westinghouse  air- 
brakes and  signals 417 


XXIX.    CONCRETE  AND  ITS  REINFORCEMENT 

Pouring  and  ramming  are  easier  and  cheaper  than  cutting 
and  carving.  Concrete  for  dwellings  ensures  comfort  and 
safety  from  fire.  Strengthened  with  steel  it  builds  ware- 
houses, factories  and  bridges  of  new  excellence  ....  429 


XXX.    MOTIVE     POWERS     PRODUCED    WITH     NEW 

ECONOMY 

Improvements  in  steam  practice.  Mechanical  draft  Auto- 
matic stokers.  Better  boilers.  Superheaters.  Economical 
condensers.  Steam  turbines  on  land  and  sea 446 


XXXI.    MOTIVE  POWERS,  CONTINUED.     HEATING  SER- 
VICES 

Producer  gas.  Mond  gas.  Gas  engines.  Steam  and  gas 
engines  compared.  Diesel  engine  best  heat  motor  of  all. 
Gasoline  motors.  Alcohol  engines.  Steam  and  gas  motors 
united.  Heat  and  power  production  together.  District 
steam  heating.  Isolated  plants.  Electric  traction.  Gas  for 
a  service  of  heat,  light  and  power 457 


xii  CONTENTS 

XXXII.    A  FEW  SOCIAL  ASPECTS  OF  INVENTION 

Why  cities  gain  at  the  expense  of  the  country.  The  factory 
system.  Small  shops  multiplied.  Subdivided  labor  has 
passed  due  bounds  and  is  being  modified.  Tendencies 
against  centralization  and  monopoly.  Dwellings  united  for 
new  services.  Self-contained  houses  warmed  from  a 
center.  The  literature  of  invention  and  discovery  as  pur- 
veyed in  public  libraries 478 

INDEX ,489 


LIST  OF  ILLUSTRATIONS 

PROFESSOR  ALEXANDER  GRAHAM  BELL Frontispiece 

BELL  HOMESTEAD,  BRANTFORD,  ONTARIO facing  2 

Lens  of  ice  focussing  a  sunbeam 5 

Rubber  strip  suspended  plank-wise  and  joist-wise 7 

Board  doubled  breadthwise  and  edgewise 7 

Telegraph  poles  under  compression.  Wires  under  tension . .  8 
Rubber  cylinder,  flattened  by  compression,  lengthened  by 

tension  9 

Rubber  joist  compressed  along  top,  extended  along  bottom. .  10 

Girder  cut  from  joist 10 

Rubber  I-beam  suspended  flatwise  and  edgewise 10 

Girder  contours  simple,  built  up,  in  locomotive  draw-bars  ...  1 1 

Steel  ore  car 12 

Bulb  angle  column,  New  York  Subway 12 

Strap  rail  and  stringer,  Mohawk  &  Hudson  R.  R.,  1830 13 

PLIMMON  H.  DUDLEY facing  14 

Dudley  rails  16 

Steel  cross-ties  and  rails 17 

King-post  truss 18 

Frames  of  four  sides 19 

Cross-section  Arctic  ship  "Roosevelt" 20 

Pair  of  compasses  stretch  a  rubber  strip 20 

Queen-post  truss 21 

Upper  part  of  roof  truss,  Interborough  Power  House,  New 

York  21 

Two  queen-post  trusses  from  a  bridge 22 

Palladio  trusses 22 

Burr  Bridge,  Waterford,  N.  Y 23 

Howe  and  Pratt  trusses 24 

Baltimore  truss 25 


xiv  LIST  OF  ILLUSTRATIONS 

Whipple  Bridge 25 

Simple  cantilevers 26 

Victoria  Bridge,  Montreal,  original  form 27 

Victoria  Bridge,  Montreal,  present  form 28 

Cantilever  Bridge,  near  Quebec 29 

Kentucky  River  Cantilever  Bridge 30 

Arch  Bridge,  Niagara  Falls 31 

Bowstring  Bridge,  Philadelphia 32 

Williamsburg  Bridge,  New  York  City 33 

Continuous  Girder  Bridge,  Lachine,  near  Montreal 34 

Rubber  strip  supported  at  4  points,  and  at  2  points 34 

Plate  girder  bridge 35 

Lattice  girder  bridge,  showing  rivets 36 

Bookshelf  laden  and  unladen,  showing  camber 36 

Pin  connecting  parts  of  bridge 37 

Bridge  rollers  in  section  and  in  plan 38 

Girder  sections  in  various  forms _._ 39 

Rubber  cylinders  solid  and  hollow  compared  in  sag 40 

Handle  bar  of  bicycle  in  steel  tubing 40 

A  sulky  in  steel  tubing 41 

Pneumatic  hammer  in  steel  tubing 41 

Fishing  rod  in  steel  tubing 41 

Bridge  of  steel  pipe , 41 

Arch  bridge  of  steel  pipe 42 

Spiral    fire-lighter 42 

Spiral  weld  steel  tube 42 

Largest  stone  arch  in  the  world,  Plauen,  Germany 43 

Church  of  St.  Remy,  Rheims,  France 43 

Curve  of  suspended  chain 44 

Dam  across  Bear  Valley,  California 44 

Ferguson  locking-bar 45 

Hand-hole  plates,  Erie  City  water-tube  boiler 46 

Bullock  cart  with  solid  wheels 47 

Ball  thrust  collar  bearings 48 

Rigid  bearings  for  axles  of  automobiles 48 

Hyatt  helical  roller  bearing.    Ditto  supporting  an  axle 49 

Treads  and  risers  of  stairs  joined  by  curves 49 

Corner  Madison  Square  Garden,  New  York 50 


LIST  OF  ILLUSTRATIONS  xv 

Two  pipes  with  funnel-shaped  junction 50 

MODEL  BASIN,  U.  S.  NAVY,  WASHINGTON,  D.  C facing  54 

Viking   Ship 56 

Clipper  ship  "Young  America". 58 

Steamship  Kaiser  Wilhelm  II 60 

Cargo   steamer 61 

U.  S.  Torpedo-boat  destroyer 62 

Cross-sections    of    ships 63 

Racing  automobile.    Wedge  front  and  spokeless  wheels 66 

Bilgram  skew  gearing 67 

Grain    elevator 68 

Robins  conveying  belt 68 

Ewart  detachable  link  belting 69 

Curves  of  turbines 70 

Steel  vanes  of  windmill 70 

Pelton  water  wheel  and  jet 71 

Luxfer    prism 74 

Fresnel    lens 74 

Lamp  and  reflector  a  unit 75 

Inverted    arc-light 75 

Sacramento  perch  totally  reflected  in  aquarium 77 

Diagram  illustrating  total  reflection 78 

Holophane  globe,  sections 79 

Holophane  globe,  diffusing  curves 80 

Holophane  globe,  three  varieties 80 

Holophane  globe,  and  Welsbach  mantle 81 

Wire  shortened  while  original  direction  is  resumed 81 

Four  mirrors  reflect  a  ray  in  a  line  parallel  to  first  path 82 

Prisms  for  Zeiss  binocular  glasses 81 

Sections  for  Zeiss  binocular  glasses 83 

Tools  for  producing  optical  surfaces 84 

Bi-focal  lens  for  spectacles 85 

Canadian   box-stove 86 

Canadian   dumb-stove 86 

Tubing  for  radiator 87 

Gold's  electric  heater , 87 

Stolp  wired  tube  for  automobiles 87 

Corrugated   boiler 88 


xvi  LIST  OF  ILLUSTRATIONS 

Pipe  allowing  contraction  or  expansion 88 

Carving  chisels  and  gouges 90 

Lathe   cutters 90 

Ratchet  bit  brace 90 

Eskimo  skin  scraper 91 

Double  tool  drill  cutting  boiler  plate 91. 

Common  drill  compared  with  ring  drill 92 

Twist    drill 93 

How  a  tool  cuts  metal 94 

Dacotah    fire-drill 94 

Lathe,  with  parts  in  detail 95 

Compound  slide  rest 96 

Blanchard  lathe 96 

Turret  lathe,  with  side  and  top  views 97 

Ericsson's    Monitor 98 

Iron    planer  *. 99 

Iron   shaper 99 

Milling  machine 100 

Milling  cutters  with  inserted  teeth 100 

Milling  cutters  executing  curves 101 

Emery   wheels 102 

Carborundum  wheel   edges 102 

Rolls  to  reduce  steel  in  thickness 104 

Gourd-shaped  vessel,  Arkansas 108 

Gourd  and  derived  pottery  forms 109 

Pomo  basket 109 

Bilhoola   basket no 

Bilhoola  basket,  a  square  inch  of 1 1 1 

A  free-hand  scroll :  same  as  woven in 

Yokut  basket  bowl 112 

Sampler  on  cardboard 115 

Bark  vessel  and  derived  form  in  clay 115 

Vase  from  tumulus,  St.  George,  Utah 1 16 

Wooden  tray.     Clay  derivative 1 16 

Shell  vessel.     Earthen  derivative 116 

Electric  lamps  in  candle  shapes 117 

Notre  Dame  de  Bonsecours,  Montreal 118 

NEW  AMSTERDAM  THEATER,  NEW  YORK. facing  118 


LIST  OF  ILLUSTRATIONS  xvii 

Cinders  large  and  small  on  hearth 120 

Cube  subdivided  into  8  cubes 121 

Cube  built  of  27  cubes 122 

Two  rubber  strips,  varying  as  one  and  three  in  dimensions, 

compared   in   sag 127 

Air  bubbles  rising  in  oil 128 

Dvorak   sound-mill I32 

Beam  of  light  deflects  dust 133 

DR.  CARL  FREIHERR  AUER  vox  WELSBACII facing  156 

Boivin  burner  for  alcohol 157 

Alcohol  lamp  with  ventilating  hood 158 

Welsbach    mantle 159 

Tantalum  lamp 160 

Tungsten  lamp  of  Dr.  Kuzel 160 

Hewitt  mercury-vapor   lamp 161 

SECTIONS  PEARLITE  AND  STEEI facing  164 

CLEANING  CARS  BY  THE  "VACUUM"  METHOD facing  164 

Open   hearth   furnace 165 

PROFESSOR  ERNST  ABBE facing  182 

Bliss   forming  die 184 

Bliss  process  of  shell  making 184 

Mandolin  pressed  in  aluminium 185 

Pressed  seamless  pitcher 185 

Barrel  of  pressed  steel 185 

Range  front  of  pressed  steel .    186 

Pressed  paint  tube  and  cover 186 

Norwegian    cooker 189 

Aladdin    oven 190 

Mayer's   floating  magnets 193 

Alum  crystal,  broken  and  restored 194 

Marble  before  and  after  deformation  by  pressure 195 

PROFESSOR  ERNEST  RUTHERFORD facing  202 

PROFESSOR  A.  A.  MICHELSON     facing  214 

Michelson  interferometer 215 

Light-wave  distorted  by  heated  air 216 

Ancient  Egyptian  balance 219 

Rueprecht   balance 220 

Earnshaw  compensated  balance  wheel 223 


xviii  LIST  OF  ILLUSTRATIONS 

Riefler    clock 224 

Photometer    227 

Compass  needle  deflected  by  electric  wire 230 

Compass  needle  deflected  by  electric  coil 231 

Maxwell    galvanometer 231 

Weston   voltmeter 232 

Micrometer  caliper  measuring  i/iooo  inch 236 

Plug  and  ring  for  standard  measurements 237 

Two  lenses  as  pressed  together  by  Newton 237 

Newton's   rings 238 

Flat  jig  or  guide 239 

Deciduous   cypress 247 

Deciduous  cypress,  hypothetical  diagram 248 

Section  of  pipe  or  moor  grass ;  of  bulrush 251 

Human  hip  joint 252 

Valves  of  veins 252 

Built-up  gun 253 

Achromatic  prisms  and  lens 255 

Three   levers 256 

Arm  holding  ball 256 

Beaver   teeth 258 

Narwhal  with  twisted  tusk 259 

Lower  part  of  warrior  ants'  nest,  showing  dome „. . .  260 

Wasp  using  pebble  as  hammer 260 

Cuban  firefly 263 

DR.  R.  S.  WOODWARD facing  276 

Perforated  sails  for  ships 292 

Edison    phonograph 312 

TELEGRAPHONE 314  and  facing  314 

GRAY  TELAUTOGRAPH 315  and  facing  318 

Hussey's  mower  or  reaper 321 

Mergenthaler  linotype,  justifying  wedges 323 

Schuckers'  double- wedge  justifier 324 

Two  wedges  partly  in  contact,  and  fully  in  contact 325 

Polarized  light  shows  strains  in  glass 327 

Stop-motion   330 

Dexter  feeding  mechanism. 331 

Schumann's  "Traumerei"in  musical  score  and  on  Pianola  roll .  334 


LIST  OF  ILLUSTRATIONS  xix 

Mechanism  of  Pianola 335 

AUTOMATIC  TELEPHONE 336  and  facing  336 

Blenkinsop's  locomotive,  181 1 345 

Notes  on  loose  cards  in  alphabetical  order 350 

Sectional  bookcase,  desk  and  drawers 351 

Burke   telegraphic  code 353 

Burke  simplified  telegraphic  signals 354 

Pupin  long-distance  telephony 367 

Water-gauge  direct  and  reversed 370 

THOMAS  ALVA  EDISON facing  374 

Cube-root  extractor 376 

Square-root  extractor 377 

Sturtevant  ventilating  and  heating  apparatus 380 

Bicycle  suspended  from  axle 382 

Telephones  receiving  sound  through  a  beam  of  light 395 

Selenium  cylinder  with  reflector 398 

Perforated  disc  yielding  sound  from  light 399 

SIR  HENRY  BESSEMER facing  402 

First  Bessemer  converter  and  ladle 406 

New  Ingersoll  coal  cutter 418 

Drill    steels 418 

SCULPTOR  AT  WORK  WITH  PNEUMATIC  CHISEL facing  418 

Haeseler  air-hammer 419 

Rock  drill  used  as  hammer 420 

Little  Giant  wood-boring  machine 420 

Water  lifted  by  compressed  air 421 

Harris  system  of  pumping  by  compressed  air 422 

Hardie  nozzle  for  painting  by  compressed  air 423 

Vacuum  renovators  for  carpets  and  upholstery 424 

Injector  sand-blast,  Drucklieb's 425 

Vertical  receiver,  inter-  and  outer-cooler 426 

Concrete  silo  foundation 431 

Concrete  silo 432 

MANSION  IN  CONCRETE,  FORT  THOMAS,  KENTUCKY,  .facing  432 

Wall  of  two-piece  concrete  blocks 434 

Ransome  bar  for  concrete 436 

Corrugated   steel   bar 436 

Thacher  bar 436 


xx  LIST  OF  ILLUSTRATIONS 

Kahn   bar 437 

Hennebique  armored  concrete  girder 437 

Monier  netting    437 

Expanded  metal  diamond  lath 438 

Tree  box  in  expanded  steel 438 

ROYAL  BANK  OF  CANADA,  HAVANA facing  438 

Lock-woven  wire  fabric 439 

Column  forms  for  concrete,  Ingalls  Building,  Cincinnati ....  440 

Section  of  chimney,  Los  Angeles,  Cal 441 

Coignet  netting  and  hook 442 

Section  of  conduit,  Newark,  N.  J 442 

Water  culvert    443 

River  des  Peres  Bridge,  Forest  Park,  St.  Louis 444 

Memorial  Bridge,  Washington,  D.  C 444 

Francis  vertical  turbine  wheel 446 

5000  HORSE- POWER  ALLIS-CHALJMERS  STEAM  ENGINE,  facing  448 

Smoke-jack    449 

POWER    HOUSE,     INTERBOROUGH     Co.,     NEW    YORK,     ex- 
terior   facing  450 

Schmidt   superheater 451 

POWER     HOUSE,     INTERBOROUGH     Co.,     NEW     YORK,     in- 
terior   facing  452 

De  Laval  steam  turbine,  sections 453 

WESTINGHOUSE- PARSONS  STEAM   TURBINE facing  454 

Combustible  gas  from  a  candle 458 

Taylor  gas-producer 460 

Four-cycle  gas  engine 463 

Fire   syringe 467 

Sturtevant  fan  wheel,  without  casing 472 

Sturtevant  Monogram  exhauster  and  solid  base  heater 473 

NEW  YORK  CENTRAL  R.  R.  ELECTRIC  LOCOMOTIVE  WITH 

FIVE-CAR  TRAIN facing  476 


ACKNOWLEDGMENTS 

AID  in  writing  this  volume  is  acknowledged  in  the  course  of  its 
chapters.  The  author's  grateful  thanks  are  rendered  also  to 
Dr.  L.  A.  Fischer,  of  the  Bureau  of  Standards  at  Washington, 
who  has  revised  the  paragraphs  describing  the  work  of  the 
Bureau ;  to  Mr.  C.  R.  Mann  of  the  Ryerson  Physical  Laboratory, 
University  of  Chicago,  who  corrected  the  paragraphs  on  the  inter- 
ferometer; to  Mr.  Walter  A.  Mitchell,  formerly  of  Columbia 
University,  New  York,  who  revised  most  of  the  chapters  on 
measurement.  Mr.  Thomas  E.  Fant,  Head  of  the  Department 
of  Construction  and  Repair  at  the  Navy  Yard,  Washington,  D.  C., 
gave  the  picture  of  the  model  basin  here  reproduced.  Mr.  Walter 
Hough  of  the  National  Museum,  Washington*,  D.  C.,  contributed 
a  photograph  of  the  Pomo  basket  also  reproduced  here.  Mr.  John 
Van  Vleck  and  Mr.  Henry  G.  Stott  of  New  York,  Mr.  George  R. 
Prowse  and  Mr.  Edson  L.  Pease  of  Montreal,  have  furnished 
drawings  and  photographs  for  illustrations  of  unusual  interest. 
Mr.  George  F.  C.  Smillie,  of  the  Bureau  of  Engraving,  Washing- 
ton, D.  C.,  Mr.  Percival  E.  Fansler,  Mr.  Ernest  Ingersoll,  and 
Mr.  Ashley  P.  Peck,  of  New  York,  have  read  in  proof  parts  of 
the  chapters  which  follow.  Their  corrections  and  suggestions 
have  been  indispensable. 

Professor  Bradley  Stoughton,  of  the  School  of  Mines,  Colum- 
bia University,  New  York,  has  been  good  enough  to  contribute  a 
brief  list  of  books  on  steel,  supplementing  the  chapter  on  that 
theme  written  with  his  revision.  Had  it  been  feasible,  other  chap- 
ters would  have  been  supplemented  in  like  manner  by  other 
teachers  of  mark.  In  1902  the  American  Library  Association 
published  an  annotated  guide  to  the  literature  of  American  his- 
tory, engaging  forty  critics  and  scholars  of  distinction,  with  Mr. 

xxi 


xxii  ACKNOWLEDGMENTS 

J.  N.  Larned  as  editor.  It  is  hoped  that  at  no  distant  day  guides 
on  the  same  helpful  plan  will  be  issued  in  the  field  of  science,  duly 
supplemented  and  revised  from  time  to  time. 

In  the  present  volume  the  author  has  endeavored  to  include  in 
his  survey  the  main  facts  to  the  close  of  May,  1906. 

NEW  YORK,  September,  1906. 


INVENTORS  AT  WORK 


rr  -HE 
L 

OF 


CHAPTER  I 
INTRODUCTORY 

INVENTORS  and  discoverers  are  justly  among  the  most 
JL  honored  of  men.  It  is  they  who  add  to  knowledge,  who 
bring  matter  under  subjection  both  in  form  and  substance,  who 
teach  us  how  to  perform  an  old  task,  as  lighting,  with  new  econ- 
omy, or  hand  us  gifts  wholly  new,  as  the  spectroscope  and  the 
wireless  telegraph.  It  is  they  who  tell  us  how  to  shape  an  oar 
into  a  rudder,  and  direct  a  task  with  our  brains  instead  of  tugging 
at  it  with  our  muscles.  They  enable  us  to  replace  loss  with  gain, 
waste  with  thrift,  weariness  with  comfort,  hazard  with  safety. 
And,  chief  service  of  all,  they  bring  us  to  understand  more  and 
more  of  that  involved  drama  of  which  this  planet  is  by  turns  the 
stage  and  the  spectator's  gallery.  The  main  difference  between 
humanity  to-day  and  its  lowly  ancestry  of  the  tree-top  and  the 
cave  has  been  worked  out  by  the  inventors  and  discoverers  who 
have  steadily  lifted  the  plane  of  life,  made  it  broader  and  better 
with  every  passing  year. 

On  a  theme  so  vast  as  the  labors  of  these  men  a  threshold  book 
can  offer  but  a  few  glances  at  principles  of  moment,  to  which 
the  reader  may  add  as  he  pleases  from  observations  and  ex- 
periments of  his  own.  At  the  outset  Form  will  engage  our 
regard :  first,  as  bestowed  so  as  to  be  retained  by  girders,  trusses 
and  bridges;  next,  as  embodied  in  structures  which  minimize 
friction,  such  as  well  designed  ships ;  or  as  conducing  to  the  effi- 
ciency of  tools  and  machines ;  or  deciding  how  best  heat  may  be 
radiated  or  light  diffused.  A  word  will  follow  as  to  modes  of 
conferring  form,  the  influence  on  form  of  the  materials  employed, 
and  the  undue  vitality  of  old  forms  that  should  long  ago  have 
bidden  us  good-by.  Structures  alike  in  shape  may  differ  in 
size.  Bigness  has  its  economies,  and  so  has  smallness.  Both  will 
have  brief  attention,  with  a  rapid  survey  of  new  materials  which 


2  INTRODUCTORY 

enable  a  builder  to  rear  towers  or  engines  bolder  in  dimensions 
than  were  hitherto  possible. 

Substance,  as  important  as  form,  will  next  receive  a  glance. 
First  a  word  will  be  said  about  the  properties  of  food,  raiment, 
shelter,  weapons  and  tools.  Then,  the  properties  of  fuels  and 
light-givers  will  be  considered,  as  steadily  improved  in  their  ef- 
fectiveness. How  properties  are  modified  by  heat  and  electricity 
will  be  remarked,  with  illustrations  from  steels  of  new  and  aston- 
ishing qualities,  and  from  notable  varieties  of  glass  produced  at 
Jena.  A  few  pages  will  recount  some  of  the  striking  phenomena 
of  radio-activity  displayed  by  radium,  thorium  and  kindred  sub- 
stances, phenomena  which  are  remolding  the  fundamental  con- 
ceptions of  physics  and  chemistry. 

A  survey  of  form  and  properties,  however  cursory,  must  in- 
volve measurement,  otherwise  an  inventor  cannot  with  accuracy 
embody  a  plan  in  a  working  machine,  or  know  exactly  how  strong, 
elastic,  or  conducting  a  rod,  a  wire,  or  a  frame  is.  Measuring 
instruments  will  be  sketched,  their  use  delineated,  and  the  results 
of  precise  measurement  noted  as  an  aid  to  the  construction  of 
modern  mechanism,  the  interchangeability  of  its  parts,  the  econ- 
omy of  materials  and  of  energy  in  every  branch  of  industry. 
Next  will  follow  a  chapter  noting  tasks  which  Nature  has  long 
accomplished,  and  which  Art  has  still  to  perform,  as  in  convert- 
ing at  ordinary  temperatures  within  the  human  body  fuel  energy 
into  work.  Plainly,  a  broad  field  opens  to  future  invention  as  it 
copies  the  function  of  plants  and  animals;  functions  to  be  first 
carefully  observed,  then  explained  and  at  last  imitated  with  the 
least  possible  waste  of  effort. 

The  equipment  and  the  talents  for  invention  and  discovery  are 
now  touched  upon.  First,  knowledge,  especially  as  the  fruit  of 
disinterested  inquiry;  Observation,  as  exercised  by  trained  intel- 
ligence calling  to  its  aid  the  best  modern  instruments;  Experi- 
ment, as  an  educated  passion  for  building  on  original  lines.  Then, 
in  the  mechanical  field,  we  bestow  a  few  glances  at  self-acting 
machines,  at  the  simplicity  of  design  which  makes  for  economy 
not  only  in  building,  but  in  operation  and  maintenance.  Either 
in  designing  a  new  machine,  or  in  reaching  a  great  truth,  such  as 
Universal  Development,  there  is  scope  for  Imagination  upon 


INTRODUCTORY  3 

which  we  next  pause  for  a  moment.  A  succeeding  chapter  out- 
lines how  theories  may  be  launched  and  tested,  how  analogy  may 
yield  a  golden  hint,  the  profit  in  rules  that  work  both  ways,  or 
even  in  doing  just  the  opposite  of  what  has  been  done  without 
question  for  ages  past. 

From  this  brief  consideration  of  method  we  now  pass  to  a  few 
men  who  have  exemplified  method  on  the  loftiest  plane ;  we  come 
into  the  presence  of  Newton,  the  supreme  generalizer,  and  ob- 
serve his  patience  and  conscientiousness,  as  remarkable  as  his 
resourcefulness  in  experiment,  in  mathematical  analysis.  Even 
greater  in  experiment,  while  lacking  mathematical  power,  is 
Faraday,  who  next  enlists  our  regard.  This  great  man,  more 
than  any  other  investigator,  laid  the  foundations  of  modern  elec- 
trical science  and  art.  Moreover  he  distinctly  saw  how  matter 
might  reveal  itself  in  the  'radiant*  condition  now  engaging  the 
study  of  the  foremost  inquirers  in  physics. 

Electricity  has  no  instrument  more  useful  in  daily  life,  or  in 
pure  research,  than  the  telephone.  Now  follows  a  narration  by  its 
creator,  Professor  Bell,  of  his  photophone  which  transmits  speech 
by  a  beam  of  light.  This  recital  shows  us  how  an  inventor  of  the 
first  rank  proceeds  from  one  attempt  to  another,  until  his  toil  is 
crowned  with  success.  Next  we  hear  the  story  of  the  Bessemer 
process  from  the  lips  of  Sir  Henry  Bessemer  himself,  affording  us 
an  insight  into  the  methods  and  characteristics  of  a  mind  in- 
genious, versatile  and  bold  in  the  highest  degree.  An  inventor 
of  quite  other  type  is  next  introduced,— Nobel,  who  gave 
dynamite  to  the  quarryman  and  miner,  smokeless  powder  to  the 
gunner  and  sportsman.  His  unfaltering  heart,  beset  as  he  was 
by  constant  peril,  marks  him  a  hero  as  brave  as  ever  fought 
hazardous  and  dreary  campaigns  to  a  victorious  close. 

Many  advances  in  mechanical  and  structural  art  have  been  won 
rather  through  a  succession  of  attacks  by  one  leader  after  another, 
than  by  a  single  decisive  blow  from  a  Watt  or  an  Edison.  A  great 
band  of  inventors,  improvers,  adapters,  have  accomplished  notable 
tasks  with  no  record  of  such  a  feat  as  Bessemer  with  his  con- 
verter, or  Abbe  with  Jena  glass.  A  brief  chapter  deals  with  some 
of  the  principal  uses  of  compressed  airman  agent  of  steadily  in- 
creasing range.  As  useful,  in  a  totally  different  sphere— that  of 


4  INTRODUCTORY 

building  material— is  concrete,  especially  as  reinforced  with  steel. 
A  sketch  of  its  applications  is  offered.  Then  follows  the  theme 
of  using  fuels  with  economy,  of  obtaining  from  them  motive 
powers  with  the  least  possible  loss.  This  field  is  to-day  attracting 
inventors  of  eminent  ability,  with  the  prospect  that  soon  motive 
powers  will  be  much  cheapened,  with  incidental  abridgment  of 
drudgery,  a  new  expansion  of  cities  into  the  country,  and  the 
production  of  light  at  perhaps  as  little  as  one-third  its  present 
cost.  A  page  or  two  are  next  given  to  a  few  social  aspects  of  in- 
vention, its  new  aid  and  comfort  to  craftsmen,  farmers,  house- 
holders comparatively  poor.  It  will  appear  that  forces  working 
against  the  undue  centralization  of  industry  grow  stronger  every 
day. 

A  closing  word  gives  the  reader,  especially  the  young  reader,  a 
hint  or  two  in  case  he  wishes  to  pursue  paths  of  study  the  first 
steps  of  which  are  taken  in  this  book. 

In  1900  was  published  the  author's  "Flame,  Electricity  and  the 
Camera,"  in  which  are  treated  some  of  the  principal  applications 
of  heat,  electricity  and  photography  as  exemplified  at  the  time  of 
writing.  That  volume  may  supplement  the  book  now  in  the 
reader's  hands. 


CHAPTER  II 
FORM 

Form  as  important  as  substance  .  .  .  Why  a  joist  is  stifTcr  than  a  plank  .  . 
The  girder  is  developed  from  a  joist  .  .  .   Railroad  rails  are  girders  of 
great  efficiency  as  designed  and  tested  by  Mr.  P.  H.  Dudley. 

ONE  January  morning  in  Canada  I  saw  a  striking  experiment. 
The  sun  was  shining  from  an  unclouded  sky,  while  in  the 
shade  a  Fahrenheit  thermometer  stood  at  about  twenty  degrees 
below  zero.    A  skilful  friend  of  mine  had  moulded  a  cake  of  ice 


A  lens  of  ice  focussing  a  sunbeam. 

into  a  lens  as  large  as  a  reading  glass ;  tightly  fastened  in  a  wood- 
en hoop  it  focussed  in  the  open  air  a  sunbeam  so  as  to  set  fire 
to  a  sheet  of  paper,  and  char  on  a  cedar  shingle  a  series  of  zigzag 
lines.  There,  indeed,  was  proof  of  the  importance  of  form.  To 
have  kept  our  hands  in  contact  with  the  ice  would  have  frozen 
them  in  a  few  minutes,  but  by  virtue  of  its  curved  surfaces  the 
ice  so  concentrated  the  solar  beam  as  readily  to  kindle  flame. 


6  FORM 

Clearly  enough,  however  important  properties  may  be,  not  less 
so  are  the  forms  into  which  matter  may  be  fashioned  and  dis- 
posed. Let  us  consider  a  few  leading  principles  by  which  de- 
signers have  created  forms  that  have  economized  their  material, 
time  and  labor,  and  made  their  work  both  secure  and  lasting.  We 
will  begin  with  a  glance  at  the  rearing  of  shelter,  an  art  which 
commenced  with  the  putting  together  of  boughs  and  loose  stones, 
and  to-day  requires  the  utmost  skill  both  of  architects  and  en- 
gineers. 

Building  in  its  modern  development  owes  as  much  to  improve- 
ment in  form  as  to  the  use  of  stronger  materials,  brick  instead 

of  clay,  iron  and  steel  instead  of  wood.    A  stick 
Strength  and  ' 

Rigidit  as          from  a  tree  makes  a  capital  tent-pole, 

and  will  serve  just  as  well  to  sustain  the  roof 
of  a  cabin.  For  structures  so  low  and  light  it  is  not  worth  while 
to  change  the  shape  of  a  stick.  By  way  of  contrast  let  us  glance 
at  an  office  building  of  twenty-five  stories,  or  the  main  piers  of 
the  new  Quebec  Bridge  rising  330  feet  above  their  copings.  To 
compass  such  heights  stout  steel  is  necessary,  and  it  must  be  dis- 
posed in  shapes  more  efficient  than  that  of  a  cylinder,  as  we  shall 
presently  see. 

In  most  cases  strength  depends  upon  form,  in  some  cases 
strength  has  nothing  whatever  to  do  with  form ;  if  we  cut  an  iron 
bar  in  two  its  cross-section  of  say  one  square  inch  may  be  round, 
oblong,  or  of  other  contour,  while  the  effort  required  to  work  the 
dividing  shears  will  in  any  case  be  the  same.  But  shearing 
stresses,  such  as  those  here  in  play,  are  not  so  common  or  import- 
ant as  the  tension  which  tugs  the  wires  of  Brooklyn  Bridge,  or 
the  compression  which  comes  upon  a  pillar  beneath  the  dome 
of  the  national  capitol.  When  we  place  a  lintel  over  a  door  or 
a  window,  we  are  concerned  that  it  shall  not  sag  and  let  down  the 
wall  above  it  in  ruin:  we  ensure  safety  from  disaster  by  giving 
the  lintel  a  suitable  shape.  When  we  build  a  bridge  we  wish  its 
roadway  to  remain  as  level  as  possible  while  a  load  passes,  so  that 
no  hills  and  hollows  may  waste  tractive  power:  levelness  is 
secured  by  a  design  which  is  rigid  as  well  as  strong.  If  a  rail- 
road has  weak,  yielding  rails,  a  great  deal  of  energy  is  uselessly 
exerted  in  bending  the  metal  as  the  wheels  pass  by.  A  stiff  rail, 


PLANK  AND  JOIST 


giving  way  but  little,  avoids  this  waste.  To  create  forms  which 
in  use  will  firmly  keep  their  shape  is  accordingly  one  of  the  chief 
tasks  of  the  engineer  and  the  architect. 

Forms  of  this  kind,  well  exemplified  in  the  steel  columns  and 
girders  of  to-day,  have  been  arrived  at  by  pursuing  a  path  opened 
long  ago  by  some  shrewd  observer.  This  man 
noticed  that  a  plank  laid  flatwise  bent  much 
beneath  a  load,  but  that  when  the  plank  rested 
on  its  narrow  edge,  joist  fashion,  it  curved  much  less,  or  hardly 


Plank  and 
Joist. 


Rubber  strip  suspended  plank-wise,  and  joist-wise. 


Board  doubled  breadthwise  through 
small  semi-circle  AB,  then  edge- 
wise through  large  semi- 
circle CD. 


at  all.  Thus  simply  by  chang- 
ing the  position  of  his  plank 
he  in  effect  altered  its  form 
with  reference  to  the  strain  to 
be  borne,  securing  a  decided 
gain  in  rigidity.  Let  us  re- 
peat his  experiment,  using 
material  much  more  yielding 
than  wood.  We  take  a  piece 
of  rubber  eight  inches  long, 
one  inch  wide  and  one  quarter 
of  an  inch  thick.  Placing  it 
flatwise  on  supports  close  to 
its  ends  we  find  that  its  own 
weight  causes  a  decided  sag. 
We  next  place  it  edgewise, 
taking  care  to  keep  it  perpen- 


8 


FORM 


dicular  throughout  its  length,  when  it  sags  very  little.  Why  ?  Be- 
cause now  the  rubber  has  to  bend  through  an  arc  four  times 
greater  in  radius  than  in  the  first  experiment.  Suppose  we  had  a 
large  board  yielding  enough  to  be  bent  double,  we  can  see  that 
there  would  be  much  more  work  in  doubling  it  edgewise  than  flat- 
wise. The  rule  for  joists  is  that  breadth  for  breadth  their  stiffness 
varies  as  the  square  of  their  depth,  because  the  circle  through 
which  the  bending  takes  place  varies  in  area  as  the  square  of  its 
radius.  In  our  experiment  with  the  rubber  strip  by  increasing 
depth  four- fold,  we  accordingly  increased  stiffness  sixteen- fold ; 
but  the  breadth  of  our  rubber  when  laid  as  a  joist  is  only  one- 
fourth  of  its  breadth  taken  flatwise,  so  we  must  divide  four  into 
sixteen  and  find  that  our  net  gain  in  stiffness  is  in  this  case  four- 
fold. 

Here  let  us  for  a  moment  dwell  upon  the  two  opposite  ways  in 
which  strength  may  be  brought  into  play,  as  either  compression 

or  tension  is  resisted.     An  example  presenting 
Girders.  both   is   a  telegraph  pole,   with  well-balanced 

burdens  of  wires.    Its  own  weight  and  its  load 
of  wires,  compress  it,  as  we  can  prove  by  measuring  the  pole  as 


Telegraph  poles  under  compression.    Wires  under  tension. 


TEXSIOX  AXD  COMPRESSION 


9 


stretched  upon  the  ground  before  being  set  in  place,  and  then 
after  it  is  erected  and  duly  laden.  Should  this  downward  thrust 
be  excessive,  the  pole  would  be  crushed  and  broken  down.  The 
strung  wires  are  not  in  compression,  but  in  the  contrary  case  of 
tension,  and  are  therefore  somewhat  lengthened  as  they  pass 
from  one  pole  to  the  next.  Now  observe  a  mass  first  subjected 
to  compression,  and  next  to  tension.  In  bearing  a  pound  weight 
a  rubber  cylinder  is  compressed  and  protrudes ; 
when  the  weight  is  suspended  from  this  cylin- 
der, the  rubber  is  lengthened  by  tension.  In 
each  case  the  effect  is  vastly  greater  than  with 
wood  or  steel,  because  rubber  has  so  much  less 
stiffness  than  they  have. 

Both  tension  and  compression  are  exhibited 


Rubber  cylinder. 


Flattened 
by  compression. 


Lengthened 
by  tension. 


in  our  little  rubber  joist,  which  illustrates  the  familiar  wooden 
support  beneath  the  floors  of  our  houses.  This  form  in  giving 
rise  to  the  girder  has  been  changed  for  the  better.  Let  us  see  how. 
As  the  rubber  joist  sags  between  its  ends,  we  observe  that  its 
upper  half  is  compressed,  and  its  lower  half  extended,  the  two 
effects  though  small  being  quite  measurable.  As  we  approach 
the  central  line,  A  B,  this  compression  and  tension  gradually  fall 
19  zero;  it  is  clear  that  only  the  uppermost  and  undermost  layers 


10 


FORM 


Rubber  joist  in  section,  compressed  along  the  top,  extended 
along  the  bottom. 

fully  call  forth  the  strength  of  the  material,  the  inner  layers  doing 

so  little  that  they  may  be  re- 
moved with  hardly  any  loss. 
Hence  if  we  take  a  common 
joist  and  cut  away  all  but  an 
upper  and  lower  flange,  leav- 
ing just  web  enough  between 
to  hold  them  firmly  together, 
we  will  have  the  I-beam  which 
among  rectangular  supports  is 
strongest  and  stiffest,  weight 
for  weight.  In  producing  it 
the  engineer  has  bared  within 
the  joist  the  skeleton  which 
confers  rigidity,  stripping  oft 

all  useless  and  burdensome  clothing.  An  I-beam  made  of  rubber 
when  laid  flatwise  over  supports  at  its  ends  will  sag  much ;  when 
laid  edgewise  it  will  sag  but  little,  clearly  showing  how  due  form 
and  disposal  confer  stiffness  on  a  structure. 


Girder  cut  from  joist. 


Rubber  I-beam  suspended  flatwise,  and  edgewise. 

Girders  of  steel  are  rolled  and  riveted  together  at  the  mills  in 
a  variety  of  contours,  each  best  for  a  specific  duty,  as  the  skeleton 
of  a  floor,  a  column,  or  a  part  of  a  bridge.  Their  lengths,  if  de- 


GIRDERS 


11 


sired,  may  far  exceed  those  possible  to  wood.     Their  principal 
simple  forms  are  the  I-heam ;  T,  the  tee;  L,  the  angle;  C,  the 

channel ;  and  the  Z-bar.    Of  these  the  I- 
T      y       [_       £     "L      beam  is  oftenest  used;  its  two  parallel 

Simple  girder  contours.      flanges  are  at  the  distance  apart   which 

practice  approves,  they  are  united  by  a 

web  just  stout  enough  not  to  be  twisted  or  bent  in  sustaining  its 


Girder  contours  simple  and  built  up. 


Girder  forms  in  locomotive 
draw-bars. 


12 


FORM 


burdens.  Crank  shafts  of  engines,  to  withstand  severe  strains,  are 
built  in  girder  fashion ;  so  are  the  side-bars  of  locomotives  and  the 
braces  of  steel  cars.  Plates  riveted  together  may  serve  as  com- 
pound girders  or  columns  of  great  strength  and  rigidity.  In  the 
New  York  subway  the  riveted  steel  columns  which  support  the 


100,000  pound  steel  ore  car  built  by  the  Standard  Steel  Car  Co., 

Pittsburg,  for  the  Duluth,  Missabe  &  Northern  R.  R. 

Of  structural  steel  throughout.     Weight 

unloaded,  32,200  pounds. 

roof  have  a  contour  which  enlarges  at  the  extremities. 


Section  of  standard  bulb  angle  column,  New  York 
Subway. 


THE  FIRST  AMERICAN  RAIL  13 

By  all  odds  the  most  important  girder  is  the  rail  in  railroad 
service.     Let  us  glance  at  phases  of  its  development  in  America, 
as  illustrating  the  importance  of  a  right  form  to 
efficient  service.    At  the  outset  of  its  operations,          The  RaU. 
in  1830,  the  Mohawk  &  Hudson  Railroad,  now 
part  of  the  New  York  Central  &  Hudson  River  Railroad,  employed 
a  rail  which  was  a  mere  strap  of  iron  two  and  one  half  inches 
wide,  nine  sixteenths  of  an  inch  thick,  with  upper  corners  rounded 
to  a  breadth  of  one  and  seven  eighths  inches ;  it  was  laid  upon  a 


Cruss&xfion 

Strap  rail  and  stringer,  Mohawk  &  Hudson  R.  R.,  1830. 

pine  stringer,  or  light  joist,  six  inches  square,  and  weighed  about 
14  pounds  per  yard.  Thin  as  this  rail  was,  its  proportions  were 
adequate  to  bearing  a  wheel-flange  which  protruded  but  half  an 
inch  or  even  less.  Where  the  builders  of  that  day  sought  rigidity 
and  permanence  was  in  the  foundations  laid  beneath  their 
stringers.  Except  upon  embankments  there  were  for  each  track 
two  pits  each  two  feet  square,  three  feet  from  centre  to  centre, 
filled  with  broken  stone  upon  which  were  placed  stone  blocks  each 
of  two  cubic  feet.  On  the  heavy  embankments  cross-ties  were  laid ; 
these  were  found  to  combine  flexibility  of  superstructure  with 
elasticity  of  roadbed,  so  that  they  were  adopted  throughout  the 
remainder  of  the  track  construction  and  continue  to  this  hour 
to  be  a  standard  feature  of  railroad  building. 

It  was  soon  observed  that  the  surface  of  a  track  as  it  left  the 
track-maker's  hands,  underwent  a  depression  more  or  less  marked 
when  a  train  passed  over  it.  With  a  strap-iron  rail  this  depression 
was  so  great  that  engines  were  limited  to  a  weight  of  from  three 
to  six  tons.  Before  long  the  strap  form  was  succeeded  by  a  rail 
somewhat  resembling  in  section  the  rail  of  to-day.  Year  by  year 


14  FORM 

the  details  of  rolling  rails  were  improved,  so  that  sections  weigh- 
ing thirty-five  to  forty  pounds  to  the  yard  came  into  service. 
These  at  length  united  a  hard  bearing  surface  for  the  wheel- 
treads,  a  guide  for  the  wheel-flanges,  and  a  girder  to  carry  the 
wheel-loads  and  distribute  them  to  the  cross-ties.  Thereupon  the 
*  weights  of  engines  and  cars  were  increased,  leading,  in  turn,  to  a 
constant  demand  for  heavier  rails.  In  1865  a  bearing  surface  was 
reached  adequate  for  wheel-loads  of  10,000  to  12,000  pounds,  the 
rail  weighing  fifty-six  to  sixty  pounds  to  the  yard.  But  the  metal 
was  still  only  iron,  and  wore  rapidly  under  its  augmented  bur- 
dens. Then  was  introduced  the  epoch-making  Bessemer  process 
and  steel  was  rolled  into  rails  four  and  one-half  inches  high,  of 
fifty-six  to  sixty-five  pounds  to  the  yard,  of  ten  to  fifteen-fold 
the  durability  of  iron.  In  design  the  early  steel  rails  were  limber 
so  that  they  rapidly  cut  the  cross-ties  under  their  seats,  pushing 
away  the  ballast  beneath  them.  Because  they  lacked  height  they 
had  but  little  stiffness,  one  result  being  that  the  spikes  under  the 
rails  were  constantly  loosened,  exaggerating  the  deflection  due  to 
passing  trains.  Throughout  the  lines  every  joint  became  low,  and 
the  rails  took  on  permanent  irregularities  under  the  pounding 
of  traffic,  dealing  harmful  shocks  to  the  rolling  stock. 

This  was  the  state  of  affairs  in  1880,  when  Mr.  Plimmon  H. 
Dudley  invented  his  track-indicator.  This  apparatus,  placed  in 
a  moving  car,  records  by  ever-flowing  pens 
Dudley's  Tiack  on  paper  every  irregularity,  however  slight,  in 
the  track  over  which  it  passes.  When  railroad 
engineers  first  saw  its  records,  they  believed  that  the  thing  to  do 
was  to  restore  their  roads  to  straightness  by  the  labor  of  track- 
men. It  was  abundantly  proved  that  the  real  remedy  lay  in  using 
a  rail  of  increased  stiffness,  that  is,  a  rail  higher  and  heavier. 
Mr.  Dudley,  in  the  light  of  records  covering  thousands  of  miles 
of  running,  added  fifteen  pounds  to  a  rail  which  had  weighed 
sixty-five  pounds,  and  gave  it  a  height  of  five  inches  instead  of 
four  and  one  half,  while  he  broadened  its  upper  surface.  At  a 
bound  these  changes  increased  the  stiffness  of  the  section  sixty 
per  cent.,  the  gain  being  chiefly  due  to  added  height.  Proof  of 
this  came  when  his  improved  rail  was  found  to  be  much  stiffer 
than  that  of  the  Metropolitan  Railway,  of  London,  which  weighed 


'  Photograph  by  F.  M.  Soraers.  Cincinnati,  O. 

PLIMMON   H.   DUDLEY 
OF  NEW  YORK. 


THE  DUDLEY  RAIL  15 

eighty-four  pounds  to  the  yard  and  had  a  base  of  six  and  three 
eighths  inches,  but  a  height  of  only  four  and  one  half  inches.  In 
July,  1884,  the  Dudley  rail  was  laid  in  the  Fourth  Avenue  via- 
duct, New  York ;  so  satisfactory  did  it  prove  that  in  less  than 
two  years  five-inch  rails  were  in  service  on  three  trunk  lines. 
Then  followed  their  introduction  throughout  America,  their 
smoothness  and  stability  as  a  track  giving  them  acceptance  far 
and  wide. 

The  performance  of  the  Dudley  rail  so  impressed  Mr.  William 
Ikichanan,  Superintendent  of  Motive  Power  for  the  New  York 
Central  Railroad  that  in  1889  ne  planned  his  famous  passenger 
engine,  No.  870,  which  entered  upon  active  duty  in  April,  1890. 
It  carried  40,000  pounds  upon  each  of  its  two  pairs  of  driving 
wheels,  instead  of  31,250,  as  did  its  heaviest  predecessor;  its  truck 
bore  a  burden  of  40,000  pounds  more ;  its  loaded  tender  weighed 
80,000  pounds,  making  a  total  of  100  tons,  an  advance  of  forty 
per  cent,  beyond  the  weight  of  the  heaviest  preceding  engine  and 
tender.  Mr.  Buchanan's  forward  stride  has  been  worthily  fol- 
lowed up.  Since  1890,  passenger  locomotives  have  nearly  doubled 
in  the  weight  borne  upon  their  axles,  while  tractive  power  has 
increased  in  the  same  degree.  Through  express  and  mail  trains 
have  more  than  doubled  in  weight,  and  their  speeds  have  increased 
thirty  to  forty  per  cent.  The  tonnage  of  an  average  freight  train 
has  been  augmented  four  to  six-fold,  with  reduction  of  the  crews 
necessary  to  keep  a  given  amount  of  tonnage  in  motion.  This 
economy  is  reflected  in  a  reduction  of  rates  which  are  now  in 
America  the  lowest  in  the  world,  and  which  steadily  fall.  In 
capacity  for  business  united  with  stability  of  roadbed,  mainly 
due  to  stronger  and  stiffer  rails  and  to  adapted  improvement  in 
rolling  stock,  railroad  progress  in  the  past  fifteen  years  is  equal 
to  that  of  the  sixty  years  preceding.  With  rails  increased  to  a 
weight  of  loo  pounds  to  the  yard  there  is  shown,  even  in  passing 
over  the  joints,  an  astonishing  degree  of  smoothness  as  con- 
trasted with  the  jolting  action  of  rails  comparatively  low  and 
light.  Stiffness  of  rail  reduces  the  destructive  action  of  service, 
originally  enormous,  upon  both  equipment  and  track,  lowering  in 
a  marked  degree  the  cost  of  maintenance.  Size  of  rail  as  well 
as  form  plays  a  part  in  this  economy.  A  passenger  train  weigh- 


16*  FORM 

ing  378  tons  has  required  820  horse  power  on  65-pound  rails,  am! 
but  720  horse  power  on  8o-pound  rails,  the  speed  in  both  cases 
being  55  miles  an  hour;  it  is  estimated  that  with  io5~pound  rails 
620  horse  power  would  have  sufficed.  In  freight  service  Dudley 


(80  Ibs-peryrf} 


(lOOIb&peryd) 


Dudley  rails. 


rails  have  reduced  the  resistances  per  ton  from  between  7  and 
8  pounds  to  one  half  as  much;  a  further  reduction,  to  3  pounds, 
is  in  prospect.  In  passenger  service,  with  rails  of  unimproved 
type  the  resistance  at  52  miles  an  hour  is  12  pounds  per  ton; 
with  Dudley  rails  this  resistance  for  heavy  trains  is  not  aug- 
mented when  the  speed  rises  to  65  or  70  miles  an  hour.  Dudley 
rails,  and  rails  derived  from  their  designs,  are  now  in  use  on 
three  fourths  of  all  the  trackage  of  American  railroads,  effect- 
ing a  vast  economy.  Seventy-five  years  ago  the  DeWitt  Clinton 
locomotive  and  tender  weighed  only  five  sixths  as  much  as  the 
main  pair  of  driving  wheels,  boxes,  axle,  and  connecting  rods  of 
the  present  Atlantic  type  of  engine.  That  such  an  engine  can 
haul  a  heavy  train  at  seventy  miles  an  hour  largely  depends  upon 
the  production  of  that  simple  and  important  element  in  rail- 
roading, its  rail.1 

1  Mr.  Dudley's  rails,  and  those  of  other  designers,  are  fully  illustrated 
and  discussed  in  "Railway  Track  and  Track  Work,"  by  E.  E.  Russell 
Tratman.  Second  edition.  New  York,  Engineering  News  Publishing  Co. 


STEEL  CROSS-TIES 


17 


Steel  cross-tics  and  rails.  — Carnegie  Steel  Co.,  Pittsburg. 

In  Ninth  Street,  Pittsburg,  the  rails  of  the  traction  line  are 
for  some  distance  carried  on  steel  ties  similar  in  form,  as  here 
shown. 


CHAPTER  III 
FORM—  Continued.    BRIDGES 

Roofs  and  small  bridges  may  be  built  much  alike  .  .  .  The  queen-post 
truss,  adapted  for  bridges  in  the  sixteenth  century,  was  neglected  for 
two  hundred  years  and  more  ...  A  truss  bridge  replaces  the  Victoria 
Tubular  Bridge  .  .  .  Cantilever  spans  at  Niagara  and  Quebec  .  .  .  Sus- 
pension bridges  at  New  York  .  .  .  The  bowstring  design  is  an  arch 
disguised  .  .  .  Why  bridges  are  built  with  a  slight  upward  curve  .  .  . 
How  bridges  are  fastened  together  in  America  and  England. 

RAILS  are  girders  used  by  themselves  :  girders  are  often  com- 
bined in  trusses;  of  these  much  the  largest  and  most  im- 
portant are  employed  for  bridges.    There  is  now  under  construc- 
tion near  Quebec  a  cantilever  bridge  whose  channel  span  of  1,800 
feet   will   be  the   longest   in   the   world.      See 


Roofs  and  Bridges 
Much  Alike. 


pa 


jt    wijj    take    us    a    little    while    to 


understand  how  so  bold  a  flight  as  this  was 
ever  dared.  We  will  begin  with  a  glance  at  a  truss  of  the  simplest 
sort,  such  as  we  may  find  beneath  the  roof  of  an  old-fashioned 
barn.  A  pair  of  rafters,  AB  and  AC,  are  inclined  to  each  other 
at  an  obtuse  angle,  and  are  fastened  to  the  horizontal  beam,  BC, 

at  B  and  C.  Their  apex, 
A,  is  joined  to  BC  by  the 
king-post,  AK,  which  binds 
the  three  strongly  and  firm- 
ly. This  whole  structure 
makes  up  a  triangle,  and  so 
does  each  of  its  halves, 
ABK  and  AKC.  No  other 
shape  built  of  straight 

King-post  truss.    AK,  king-post.  PieC6S   wil1   kee?    its    form 

under     strain.      Take     in 

proof   say    four   pieces   of 

lath  and  unite  them  with  a  freely  turning  pin  at  each  corner  to 
make  the  frame,  ABCD ;  it  is  easily  distorted  by  a  slight  pull  or 

18 


RIGIDITY  OF  TRIANGLES 


19 


n 


B 


n 


push ;  but  insert*  cross-pieces,  AC  and  BD  so  as  to  divide  the 
square  into  triangles,  and  at  once  the 
frame  resists  any  strain  not  severe 
enough  to  break  the  wood  or  crush 
its  fastenings.  As  the  roof  presses 
down  the  frame  ABC,  its  sides,  AB 
and  AC,  tend  to  slide  away  at  their 
lower  ends,  B  and  C,  but  this  is  pre- 
vented by  the  horizontal  beam,  BC, 
which  while  it  holds  them  in  place  is 
itself  so  stretched  as  to  be  held  level 
and  straight.  This  calling  into  play  of 
tension  constitutes  the  chief  merit  of 
the  truss,  and  enables  it  in  roofs  and 
bridges  to  span  breadths  impossible  to 
simple  beams  bending  downward  un- 
der compressive  strains.  Not  only  in 
houses,  but  in  ships,  the  truss  has 
great  value;  it  was  introduced  in  this 
field  by  Robert  Seppings  of  Chatham, 
in  England,  about  1810.  To  resist  the 
pressure  of  grinding  ice,  the  "Roose- 
velt" is  built  with  trusses  of  great 
strength.  She  sailed  in  1905,  under 
Commander  Peary,  for  a  voyage  of 
Arctic  discovery. 

Were  our  barn  roof  flat  instead  of 
sloping  to  form  a  truss,  its  supporting  timbers,  under  compression, 
would  have  a  decided  sag  from  which  BC  is  free.  When  we 
fashion  a  small  model  of  a  king-post  truss,  its  sides,  AB  and  AC, 
must  be  of  metal  or  wood  because  they  will  be  in  compression ; 
the  king-post,  AK,  and  the  base,  BC,  which  will  be  under  tension, 
may  be  of  rubber  or  cord.  Always  as  in  this  case  the  parts  of  a 
truss  exposed  to  compression  must  be  of  rigid  material.  When  a 
part  may  be  of  cord,  rope  or  wire,  we  know  that  it  is  resisting 
tension.1 

*A  model  easily  put  together  illustrates  the  truss  in  its  simplest  form. 
Take  a  pair  of  wooden  compasses,  each  half  of  which  is  15  inches  long, 


Frames  of  four  sides.    For 

rigidity  diagonals  are 

needed,  AC,  BD. 


FORM-BRIDGES 


Cross-section   of  the   "Roosevelt,"    Commodore    Peary's 

new  Arctic  ship.     Reproduced  by  permission  from 

the  Scientific  American,  New  York. 

Wrought  iron  exerts  about  as  much  resistance  to  compression 
as  to  tension;  so  does  steel.  For  this  reason,  and  on  account  of 
their  great  strength,  they  have  immense  value  in  building.  Cast 


B 


Pair  of  compasses  stretch  a  rubber  strip. 

such  as  are  sold  for  blackboard  use  by  the  Milton  Bradley  Co.,  Spring- 
field, Mass.,  at  50  cents.  At  each  tip  fasten,  by  the  ring  provided  with 
the  compasses,  a  chair  castor  such  as  may  be  had  at  any  hardware  store. 
Join  the  tips  of  the  castors  by  a  rubber  strip.  Holding  the  compasses 
upright,  and  applying  pressure  from  the  hand,  they  will  extend  until  the 
rubber  will  be  so  stretched  as  to  become  almost  perfectly  horizontal. 
Various  weights  may  in  succession  be  suspended  from  the  compass- joint, 
replacing  manual  pressure,  and  serving  to  measure  the  exerted  tensions. 


ROOF  TRUSSES 


21 


iron  can  bear  only  about  one  sixth  as  much  tension  as  compres- 
sion, so  that  it  is  useful  as  foundations,  for  the  bed-plates  of  en- 
gines and  machinery  and  the  like,  but  is  unsuitable  for  girders. 
Wood  is  much  stronger  under  tension  than  compression ;  in  white 
pine  this  proportion  is  as  eight  to  one.  In  designing  timber 
bridges  the  strains  are,  therefore,  as  far  as  possible,  arranged  for 
tension. 

Let  us  now  enter  another  barn,  about  one  half  wider  than  the 
first,  and  look  upward  at  its  rafters.  We  see  its  roof  sustained  by 
timbers  disposed  as  DCMH, 
to  avoid  the  undue  weight 
necessary  for  a  design  re- 
sembling that  of  our  first 
roof,  ABC.  Instead  of  one 
upright  post,  AK,  as  in  that 
case,  we  have  now  two,  DE 
and  HO,  called  queen- 
posts,  sustaining  the  hori- 
zontal beam,  CM.  In 
large  modern  roofs  the 

simple  queen-post  is  modified  and  multiplied,  as  in  the  main  power 
house  of  the  Interborough  Rapid  Transit  Company,  West  5Qth  St., 
New  York.  Returning  to  our  simple  queen-post  design,  let  us 


Queen-post  truss. 
DE,    HO,  queen-posts. 


Upper  part  of  a  roof  truss. 
Interborough  Power  House,  New  York. 


imagine  a  creek  flowing  between  walls  spanned  by  DCMH ;  that 
truss  and  a  mate  to  it,  parallel  at  a  distance  of  say  ten  feet,  would 
easily  carry  a  roadway  and  give  us  a  bridge.  A  truss  for  a  bridge 


22 


FORM-BRIDGES 


must  be  much  stronger  than  for  a  roof  of  equal  span,  because  a 
bridge  has  to  bear  moving  loads  which  may  come  upon  it  sud- 


Two  queen-post  trusses  form  a  bridge. 

denly,    giving   rise   not   only   to   serious    strains    but   to    severe 
vibrations,  all  varying  from  moment  to  moment. 

The  queen-post  truss  was  remarkably  developed  by  Palladio,  a 

famous  Italian  architect  of  the  sixteenth  century.     Two  of  his 

designs,   here  given  in  outline,   are   from  his 

Palladio's  Long  k  Qn  architecture  published  in  I  s?o ;  their 

Neglected  Truss.  D/ 

contours,  little  changed,  are  in  vogue  to-day. 

Strangely  enough  the  trusses  of  Palladio,  for  all  their  merit,  passed 
out  of  notice  until  their  principles  were  revived  and  improved  by 


Palladio  trusses. 


BRIDGES  FOR  RAILROADS 


23 


Theodore  Burr,  in  1804,  in  a  wooden  bridge  over  the  Hudson  at 
Waterford,  New  York.  This  bridge  had  spans  respectively  of 
154,  1 60  and  1 80  feet,  stretches  impossible  to  single  wooden  beams. 


Burr  Bridge,  Waterford,  N.  Y. 
DO,  HE,  struts.     DE,  HO,  ties.     DHEO,  panel. 

Professor  J.  B.  Johnson,  an  eminent  engineer,  says  that  this  is  the 
most  scientific  design  ever  invented  for  an  all-wooden  bridge ; 
during  fifty  years  it  stood  unrivaled  as  a  model  for  highway  pur- 
poses in  this  country.  The  Burr  bridges  were  usually  covered  in, 
so  as  to  resemble  the  roofs  we  began  by  inspecting.  In  a  truss 
bridge  each  part  bounded  by  two  adjacent  uprights,  as  DOEH  in 
the  queen-post  figure  on  page  21,  is  a  panel;  every  part  under 
compression,  as  DO,  HE,  is  a  strut,  post,  or  column;  every  part 
subject  to  tension  as  DE,  HO,  is  a  tie. 

In  1830  as  the  first  American  railroad  train  sped  on  its  way,  a 
new  era  dawned  for  the  bridge  builder  as  well  as  for  his  neigh- 
bors. At  once  sprang  up  a  demand  for  bridges  longer  and  stronger 
than  those  which  in  the  past  had  served  well  enough.  A  score  of 
wagons  laden  with  wheat  or  potatoes  were  a  good  deal  lighter 
than  a  locomotive  followed  by  a  train  of  loaded  freight  cars.  A 
market-wagon,  too,  could  easily  be  taken  aboard  a  ferry-boat,  but 
for  an  engine  and  its  cars  a  bridge  was  imperative,  if  the  stream 
were  not  so  wide  as  to  forbid  all  opportunity  to  the  bridge  builder. 
His  response  to  the  demands  of  the  railroad  was  two-fold.  First  in 
the  use  of  metal  instead  of  wood,  beginning  with  iron  rods  to 
bind  together  frames  of  timber.  As  iron  became  cheaper  and  its 
value  more  and  more  evident,  he  employed  it  for  additional  parts 
of  his  structure  until  at  last  he  built  the  whole  bridge  of  iron. 

To-day  good  steel  is  so  cheap  that  railroad  bridges  are  seldom 
reared  of  anything  else.  Besides  using  stronger  materials,  the 


24 


FORM-BRIDGES 


designer  has  gradually  improved  the  form  of  his  structure,  not 
only  in  its  parts  but  as  a  whole,  so  that  to-day,  strength  for 
strength,  a  bridge  may  be  only  one  tenth  as  heavy  as  a  bridge  of 
fifty  years  ago.  Advances  in  form  have  been  due  to  experience 
as  one  type  has  been  compared  with  another;  meanwhile  the 
mathematicians  have  carried  their  analysis  of  strains  as  far  as 
the  extreme  complexity  of  their  problems  will  allow,  greatly  to 
the  betterment  of  designs. 

In  building  a  bridge,  as  in  rearing  many  other  structures,  gir- 
ders of  various  contours  are  used.  In  bridge  building  the  I- 
beam  is  most  employed.  When  the  roadway  proceeds  on  the  top 
chord,  as  DH,  in  the  queen-post  figure,  page  21,  we  have  a  deck 
bridge;  when  it  is  built  on  the  bottom  chord,  as  CM,  we  have  a 
through  bridge. 

The  Burr  bridge  of  1804,  already  mentioned,  included  an  arch 

and  was  in  part  sustained  by  struts  projecting  from  abutments. 

These  features  were  omitted  by  William  Howe 

The  Burr  Bridge    m  t^ie  Bridge  which  he  patented  in  1840,  and 

Simplified  by       which  was,  as  far  as  is  known,  the  first  suc- 

Howe  and  Pratt,    cessor  to  a  design  of  Palladio  in  employing  a 

simple  truss  for  long  spans.     The  Howe  truss 


HOWE  TRUSS 


PRATT  TRUSS 


was  built  of  wood,  except  its  terminal  tie-rods,  which  were  of 
iron;  it  has  been  repeated  thousands  of  times  throughout  the 


STRAINS  UNIFORM 


25 


world.  In  1844  Thomas  W.  and  Caleb  Pratt  patented  a  bridge 
which  in  design  was  the  converse  of  Howe's.  Its  diagonals  of 
iron  were  used  in  tension,  while  its  vertical  struts  of  timber  were 
in  compression ;  in  the  Howe  pattern  the  diagonals  were  in  com- 
pression, the  verticals  in  tension.  This  plan,  by  shortening  the 
struts,  diminished  the  cross-section  necessary  in  a  truss.  When 
wrought  iron  took  the  place  of  wood  for  bridges,  the  Pratt 
design  became  the  most  popular  of  all,  combining  as  it  did  more 
desirable  features  than  any  of  its  rivals.  To-day  for  long  spans 


Diagram  of  Baltimore  truss. 

the  Baltimore  truss  is  much  in  favor.  Its  stresses,  that  is,  its  re- 
sistances to  change  of  form  under  strain,  are  readily  ascertained ; 
the  shortness  of  its  panels  means  strength ;  and  its  diagonals  have 
the  inclination  which  wide  and  varied  experience  has  shown  most 
desirable.  The  roadway,  it  will  be  observed,  is  upheld  by  sub- 
verticals,  that  is,  by  verticals  which  reach  the  floor  from  half  the 
height  of  a  panel. 

An  important  study  concerns  itself  with  the  intensity  and  dis- 
tribution of  strains,  first  in  girders,  next  in  trusses,  and  lastly,  in 
bridges  as  units,  all  with  intent  to  ensure  the  best  possible  designs 
throughout.  In  this  field  of  inquiry  the  pioneer  was  Squire 
Whipple,  a  maker  of  mathematical  instruments  in  Utica,  N.  Y., 
who  published  in  1847  ms  analysis  of  the  strains  in  a  truss  bridge 
due  to  its  own  weight  and  to  its  moving  loads.  With  the  laws  of 
these  strains  in  mind  he  devised  several  bridges  of  great  merit, 


Whipple  Bridge. 


26 


FORM-BRIDGES 


the  most  noteworthy  being  reared  in  1852  on  the  Rensselaer  & 
Saratoga  Railroad,  seven  miles  north  of  Troy,  which  did  service 
until  1883 ;  its  sides  or  web  system  had  ties  extended  across  two 
panels  in  double  intersection 

In  a  long  truss  bridge,  which  in  its  entirety  may  be  regarded 
as  .a  girder  of  the  utmost  size,  the  cross  pieces  between  the  main 
beams  of  the  structure  are  much  less  heavy  than  if  continuous 
plates,  of  no  more  strength.  The  original  form  of  the  Victoria 
Bridge  at  Montreal  was  that  of  a  continuous  tube  of  iron,  square 
in  section ;  it  has  given  place  to  a  truss  bridge  of  five  times  greater 
capacity  which  weighs  only  twice  as  much.  (Illustrations  of  both 
on  pages  27  and  28.) 

Thus  to  lessen  weight  in  comparison  with  strength  is  a  matter 
of  great  importance  in  a  suspended  structure,  which  must  not 
only  bear  its  own  weight,  but  carry  heavy  moving  loads. 

In  most  cases  a  bridge  crosses  a  valley  or  a  river  in  a  place 
which  , permits  the  engineer  to  erect  scaffolding  to  support  his 

Advantages  of  the  trtlsses   untl^  tnev  can  ^e  united  and  become 
Cantilever,  Arch,  self-sustaining.     In  some  places  this  course  is 
and  Bowstring  denied ;  a  river  such  as  the  Ohio  or  the  Missis- 
Designs.  sii  mav  nave  to  ke  Spanne(i  at  a  point  where  the 


Simple  cantilevers. 

FG,  HI,  are  first  separate;  then  in  contact;  last  are  joined  by  a 
plank  laid  above  them. 


27 


«  g 

H  o 

O  ^ 

S  £ 

w"  "S 

s  I 

i  -8 

«  e 


§  s 

Bi 

M 

•a 


28 


FORM-BRIDGES 


g  zi 

i  i 

^  -M 

g  a 

S  '* 

2  ^ 

PQ  '3 


BRIDGES 


29 


30 


FORM-BRIDGES 


waters  in  a  single  day  may  rise  forty  feet,  bearing  along  trees  and 
timbers  with  destructive  violence.  As  a  rule  the  difficulty  is  met  by 
employing  cantilever  spans  which  require  no  scaffolding  for  their 
construction.  To  understand  their  principle  let  us  suppose  that 
on  opposite  banks  of  a  creek  we  roll  out  to  meet  each  other  the 
joists  FG  and  HI,  taking  care  that  the  parts  over  the  water  shall 
always  be  lighter  than  the  parts  on  land.  When  the  joists  at  last 
touch  they  are  secured  to  each  other  as  a  continuous  roadway.  Or, 
while  they  are  at  a  moderate  distance  apart  they  may  be  joined 
by  a  third  timber  laid  across  the  gap  from  one  to  the  other.  In 
practice  the  simple  principle  thus  illustrated  is  developed  and 
varied  in  many  ways,  but  in  every  application  the  one  rule  is  that 
the  trusses  as  they  stretch  out  from  the  two  sides  of  a  pier  shall 
balance  each  other,  the  shore  ends  being  duly  weighted  down  or 
safely  anchored  to  solid  rock.  And  thus,  at  length,  we  come  to 
the  wonderful  bridge,  six  miles  west  of  Quebec,  whose  channel 
span  of  i, 800  feet  will  be  the  longest  ever  reared.  See  illustration, 
page  29.  From  the  cantilever  arms,  DA  and  BE,  will  be  suspended 
the  central  truss,  AB,  of  675  feet.  A  cantilever  span  may  be  much 
longer  than  a  simple  truss  because  on  a  pier,  as  D  of  this  bridge, 
a  part,  DA,  of  the  whole  span,  DE,  is  balanced  either,  as  in  this 
case,  by  a  shore  span,  CD,  or  by  a  corresponding  part  of  the  next 


Kentucky  river  cantilever  bridge 


ARCH  AND  BOWSTRING  BRIDGES    31 

span  should  that  span  not  extend  to  the  shore  but  pass  from  one 
pier  to  another. 

The  first  cantilever  bridge  in  America  was  designed  by  C. 
Shaler  Smith  for  the  Cincinnati  Southern  Railroad,  to  cross  the 
Kentucky  River;  it  was  built  in  1876-7. 

Spanning  the  gorge  of  Niagara,  close  to  the  Falls,  \is  an  arch 


Arch  bridge,  Niagara  Falls 

bridge  of  840  feet  in  its  central  span,  which,  in  its  construction 
during  1898,  followed  the  plan  originated  by  James  B.  Eads  in 
building  the  St.  Louis  bridge  nearly  thirty  years  before.  As  scaf- 
folding was  out  of  the  question  in  both  cases,  each  bridge  was 
built  out  from  its  piers  on  the  cantilever  principle.  An  arch  is 
sometimes  disguised  as  a  modified  bowstring,  as  in  the  Burr  de- 
sign of  1804,  a  horizontal  tie  connecting  the  extremities  of  the 
arched  rib  and  taking  its  thrust,  dispensing  with  the  abutments 
demanded  by  an  arch.  In  the  chords  of  such  a  pattern  the  strength 
comes  as  near  to  uniformity  throughout  as  practical  considera- 
tions permit,  avoiding  the  losses  of  early  days  when  one  part  of  a 
bridge  might  be  twice  as  strong  as  another.  The  bowstring  was 
adopted  for  the  great  span  of  542^2  feet  over  the  Ohio  at  Cin- 
cinnati built  in  1888,  and  for  the  span  of  5463/2  feet  erected  at 
Louisville  in  1893.  A  bowstring  533  feet  long,  forming  part  of 
the  Delaware  river  bridge  of  the  Pennsylvania  Railroad,  built  in 
1896,  in  Philadelphia,  is  outlined  on  page  32.  At  Bonn,  on  the 
Rhine,  there  was  completed  in  1904  a  bridge  whose  central  span 
is  a  bowstring  6i6^4  feet  long. 


32 


FORM-BRIDGES 


Bowstring  Bridge,  Pennsylvania  R.  R.,  Philadelphia. 


If  we  take  the  design  of  an  arch  bridge  and  turn  it  upside  down 
we  have  a  contour  such  as  that  of  the  Williamsburg  Suspension 
Suspension  Bridges  Bridge,  opened  in  1903  between  Brooklyn  and 

and  Continuous  Manhattan,  depicted  on  page  33.  For  the  ut- 
Girders.  most  length  this  is  the  only  available  span;  it 

brings  into  play  the  tensile  strength  of  wire,  the  strongest  form 
that  steel  can  take.  A  steel  cable  of  suitable  diameter,  if  it  had  to 
support  only  itself,  might  safely  be  three  miles  long.  A  suspen- 
sion bridge  has  another  advantage  in  employing  an  anchorage  to 
bear  strains  which  would  break  down  a  simple  truss  resting  on 
piers.  As  first  erected  suspension  bridges  were  liable  to  extreme 
and  harmful  vibration,  in  many  cases  being  shaken  to  pieces  by 
storms  of  no  great  violence.  It  was  found  that  this  vibration  was 
checked  and  that  safety  was  ensured  by  introducing  stiffening 
trusses  which,  at  the  same  time,  benefited  the  bridge  by  distribut- 
ing the  load  uniformly  throughout  the  sustaining  cables. 

At  Lachine,  about  eight  miles  west  of  Montreal,  on  the  line  of 
the  Canadian  Pacific  Railroad,  a  remarkable  bridge  crosses  the 
St.  Lawrence  river.  Its  design  is  that  of  a  continuous  girder  of 
four  spans,  the  two  side  spans  being  269  feet  each  in  length,  and 
the  two  others  each  408  feet.  This  type  is  discussed  by  Mr.  Mans- 
field Merriman  and  Mr.  Henry  S.  Jacoby  in  Part  IV,  page  30,  of 
their  work  on  Roofs  and  Bridges.  One  of  the  advantages  pre- 
sented is  that  deflection  under  live  load  is  less,  and  stiffness 
greater  than  for  simple,  discontinuous  girders,  the  harmful  effect 
of  oscillation  being  thus  diminished.  Furthermore,  less  material 
is  required  than  for  simple,  discontinuous  spans.  Both  these 


BRIDGES 


33 


34 


FORM-BRIDGES 


Continuous  girder  bridge,  Canadian  Pacific  R.  R.,  Lachine, 
near  Montreal. 


elements  of  gain  are  brought  out  in  placing  a  strip  of  rubber,  AD, 
upon  four  equidistant  points  of  support,  when  we  find  that  BC, 
the  central  third  of  the  strip  sags  less  than  either  AB  or  CD,  the 


Rubber  strip  supported,  at  4  points,  and  at  2  points. 


first  or  last  third.  Cutting  off  one-third  of  the  whole  strip  we 
deprive  the  removed  piece,  at  its  surface  of  separation,  of  the 
cohesion  which  did  much  to  keep  the  whole  strip,  before  cutting, 
almost  horizontal  at  that  point.  We  take  AB,  our  short  removed 
piece  of  rubber,  and  lay  it  at  its  ends  on  two  points  of  support; 
it  now  serves  in  a  rough-and-ready  way  as  a  model  of  a  simple 
truss,  all  by  itself ;  its  decided  sag  shows  it  much  less  rigid  than 
when  it  formed  a  part  of  an  unbroken  and  longer  structure. 
Continuous  girders  despite  their  advantages  are  seldom  em- 
ployed; they  are  liable  to  serious  difficulties;  among  these  may 
be  mentioned  that  changes,  often  unavoidable,  of.  level  in  piers 


ADAPTING  DESIGN  TO  DUTY 


35 


and  abutments  cause  them  to  suffer  great  reversals  of  stress,  al- 
ways a  source  of  danger ;  furthermore,  variations  of  length  due  to 
changes  of  temperature  are,  of  course,  much  greater  and  more 
troublesome  to  provide  against  than  in  the  case  of  discontinuous 
girders. 

Whether  spans  are  long  or  short,  engineers  are  fairly  well 
agreed  as  to  the  best  proportions  for  girders  and  panels.     They 

consider  that  a  girder  should  have  about  one- 

, ..  ,  Best  Proportions 

twelfth  to  one-tenth  as  much  depth  as  span ;  for  Spans.  ASlight 
and  that  the  weight  of  a  web  should  be  about    Upward  Curve  is 
equal  to  that  of  its  flanges.    They  usually  give   Gainful.    Pins  or 
panels  twice  as  much  depth  as  length,  with  a  Rivets  in  Fastenin£ 
tendency  to  increase  the  proportion  of  depth  to  length,  in  order 
to  minimize  the  deflections  and  oscillations  which  shorten  the 
life  of  a  structure.  For  definite  lengths  of  span,  particular  types  of 


Plate  girder  bridge. 

construction  are  preferred ;  usually  for  lengths  of  from  20  to  125 
feet,  plate  girders  are  chosen ;  for  spans  of  125  to  150  feet  riveted 
lattice  trusses  are  built ;  for  spans  of  150  to  600  feet  pin-connected 
trusses  are  employed.  Here  we  reach  the  economical  limit  of  a 
length  for  simple  trusses ;  beyond  600  feet  the  engineer  is  obliged 
to  have  recourse  either  to  a  cantilever  or  a  suspension  bridge. 


FORM-BRIDGES 


Part  of  lattice  girder  bridge,  showing  rivets. 

Whatever  the  breadth  of  the  stream  or  the  chasm  over  which 
he  is  to  build  a  roadway,  each  case  must  be  studied  in  the  light  of 
its  special  circumstances.  There  must  be  due  regard  to  business 
as  well  as  to  engineering  considerations ;  the  designer  will  bear  in 
mind  that  types  of  parts  customarily  turned  out  at  great  steel 
works  are  procurable  in  less  time,  and  at  less  cost,  than  novel  types 
requiring  to  be  manufactured  to  order.  Then,  in  speed  of  con- 
struction, he  will  remember  that  a  pin-connected  bridge  can  be 
built  much  faster  than  a  riveted  structure.  Furthermore,  every 
part  must  be  vastly  stronger  than  ordinary  duty  requires.  Tem- 
pests and  floods  may  suddenly  arise ;  at  any  instant  a  derailment  or 
a  collision  may  create  a  strain  of  the  utmost  severity;  and  even 
under  ordinary  circumstances  it  must  not  be  forgotten  that  train 
loads  grow  constantly  heavier  because  economy  lies  that  way. 


Upper  shelf,  unladen,  has  upward  curve  or  camber. 
Lower  similar  shelf  is  straightened  by  its  load. 


BRIDGE  FASTENINGS 


37 


One  detail  of  bridge  design  is  worth  a  moment's  attention. 
When  a  book-shelf  is  a  thin  board,  quite  straight  as  manufactured, 
it  sags  in  the  middle  when  fully  burdened.  This  downward  dip 
may  be  avoided  by  making  the  shelf  at  first  with  a  slight  curve 
which  brings  the  middle  a  little  higher  than  the  ends.  In  bridge 
building  a  like  curve,  or  camber,  is  given  to  each  span  so  that  when 
fully  loaded  it  will  be  level  or  nearly  so.  In  a  span  of  500  feet 
it  is  found  that  a  rise  of  half  a  foot  at  the  centre  is  sufficient.  In 
suspension  bridges,  for  the  sake  of  strengthening  the  structure, 
the  camber  far  exceeds  this  ratio. 

In  fastening  together  the  parts  of  a  bridge  the  usual  American 
practice,  already  mentioned,  is  to  employ  pins  which  pass  through 
eye  bars.  In  England  riveting  is  preferred,  as  shown  in  the  figure 
of  the  lattice  truss,  page  36.  This  difference  in  methods  arose 
through  the  use  of  materials 
which  differed.  In  the  con- 
struction of  bridges  the 
English  engineer  started 
with  the  flanged  girder  of 
cast  or  rolled  iron,  or  some 
other  form  of  stiff  beam, 
and  as  bridges  increased  in 
size  so  as  to  require  the 
framing  of  a  truss,  his 
svhole  effort  was  directed 
toward  making  that  truss  as 
much  like  the  original 
flanged  or  box  girder  as 
possible.  The  American  en- 
gineer, on  the  other  hand,  had  at  first  little  or  no  iron  or  steel  to 
work  with,  and  of  necessity  used  wood.  As  the  necessary  bridges 
were  of  considerable  span,  the  only  feasible  method  was  to  pin 
together  small  pieces  of  wood  so  as  to  form  a  connected  series  of 
triangles.  To  make  rigid  joints  in  wood  was  impracticable,  and 
indeed  rigid  joints  were  not  desired,  because  the  strength  of  wood 
is  slight  when  strains  are  applied  in  any  direction  other  than  that 
of  the  fibres  of  the  piece,  and  the  pin  joint  insures  just  this  line  of 
action.  As  a  rule  a  riveted  bridge  requires  more  metal  than  a  pin- 


Pin  connecting  parts  of  a  bridge. 


38 


FORM-BRIDGES 


connected  design,  takes  more  time  to  build,  but  demands  some- 
what less  skill.  To  provide  for  changes  in  length  as  a  bridge  is 
subjected  to  variations  of  temperature,  friction  rollers  are  used 
to  support  its  extremities.  In  the  first  suspension  bridge  at 
Niagara  Falls,  built  by  Roebling,  a  little  cement  accidentally  cov- 
ered the  friction  rollers  and 
prevented  them  from  turning ; 
fortunately  the  structure 
escaped  the  destruction  to 
which  it  was  thus  exposed. 

We  have  now  taken  a  rapid 
survey  of  some  of  the  methods 
by  which  the  designer  of 
bridges  plans  a  structure 
which  is  at  once  safe  and  to 
the  utmost  extent  economical 
of  material.  Step  by  step  he 
has  discovered  how  little  steel 
he  may  use  for  designs  all  the 
bolder  because  his  hand  is  so 
sparing  of  weight.  His  suc- 
cess began  in  adopting  the 
girder,  which  we  have  seen  to 

be  in  effect  the  working  skeleton  long  concealed  within  the  com- 
mon joist ;  the  cantilever  span  near  Quebec,  which  compasses 
i, 800  feet  in  its  flight,  has  been  dissected  out  of  preceding  burden 
bearers  in  the  same  way.  Its  metal  stands  forth  as  so  much  sheer 
muscle  kept  to  the  most  telling  lines,  unencumbered  by  a  single 
pound  of  idle  substance.  A  designer  of  such  a  fabric  is  an  artist 
skilled  in  disengaging  from  masses  of  material  every  ounce  that 
can  be  wisely  removed.  In  some  cases,  as  when  Roebling  linked 
together  New  York  and  Brooklyn,  a  bridge  is  created  as  much  a 
thing  of  beauty  as  of  use,  as  graceful  as  it  is  strong.1 

1Mr.  David  A.  Molitor  has  a  chapter,  copiously  illustrated,  on  the 
esthetic  design  of  bridges,  beginning  page  n  in  the  "Theory  and  Practice 
of  Modern  Framed  Structures,"  by  Mr.  J.  B.  Johnson  and  other  authors, 
New  York,  John  Wiley  &  Sons.  Eighth  edition,  revised  and  enlarged. 
$10.00. 


Bridge  rollers  in  section  and  plan. 
New  York,  Pennsylvania  &  Ohio  R.  R. 


CHAPTER  IV 

FORU— Continued.     WEIGHT  AND  FRICTION  DIMINISHED. 

Why  supports  are  made  hollow  .  .  .  Advantages  of  the  arch  in  buildings, 
bridges  and  dams  .  .  .  Tubes  in  manifold  new  services  .  .  .  Wheels 
more  important  than  ever  .  .  .  Angles  give  way  to  curves. 

HAVING  glanced  at  methods  by  which  forms,  judiciously 
chosen,  economize  the  materials  of  buildings  and  rails,  of 
bridges  diverse  in  type,  we  pass  to  further  consideration  of  these 
and  like  shapes,  to  find  that  they  effect  a  saving  in  material  while 
they  make  feasible  a  new  boldness  of  plan,  and  introduce  new 
elements  of  beauty.  We  will  also  remark  that  judicious  forms 
prevent  waste  of  energy  as  structures  are  either  set  in  motion,  or 
serve  to  convey  moving  bodies.  Incidentally  we  shall  see  that 
well  chosen  shapes  insure  a  structure  against  undue  hurt  and 
harm. 

In  lofty  structures,  the  box  girder  is  frequently  employed  as  a 
column  or  a  beam  because  it  has  even  greater  rigidity  than  th*» 
I-beam;  usually  it  has  four  sides,  but  it  may 
have  eight,  sixteen,  or  more,  and  thus  step  by    Hollow  Columns 

t-11  r     i   •      i         I  and  Tubes. 

step  we  come  to  a  hollow  cylindrical  column 

which  has,  indeed,  the  best  form  that  can  be  bestowed  on  sup- 


Square  Octagonal          i6-Sided 

Girder  sections. 


Round 


porting  material.     Chinese  builders  learned  its  economy  on  the 
distant  day  when  they  adopted  the  bamboo  for  their  walls  and 


FORM-HOLLOW  TUBING 


roofs.  Comparison  with  a  solid  stick  of  timber  of  like  weight  and 
substance  will  show  that  an  equal  length  of  bamboo  is  decidedly 
preferable.  The  inner  half  of  a  round  solid  stick  does  com- 
paratively little  in  holding  up  a  burden;  to  remove  that  half  is 
therefore  as  gainful  as  to  strip  from  a  joist  the  timber  surround- 
ing its  working  skeleton.  At  first  the  journals  or  axles  of  engines 
and  large  machines,  as  well  as  the  axles  of  railroad  cars  and  the 
shafts  of  steamships  were  solid;  to-day,  in  a  proportion  which 
steadily  increases,  they  are  hollow.  The  advantage  of  this  form 


Solid  rubber  cylinder  sags  much. 
Hollow  rubber  cylinder  sags  less. 

comes  out  when  we  take  two  cylinders  of  rubber,  alike  in  length 
and  weight,  one  solid,  the  other  hollow.  Supporting  both  at  their 
ends,  the  hollow  form  sags  less  than  the  solid  form,  proving  it- 
self to  be  the  more  rigid  of  the  two. 

With  like  advantage  seamless  tubing  is  adopted  for  a  broad 
variety  of  purposes.  It  builds  bicycles  and  sulkies  which  far  out- 
speed  vehicles  of  solid  frames ;  it  is 
worked  up  into  elevator  cages, 
mangle  rolls,  pneumatic  tools,  fish- 
ing-rods, magazine-rifle  tubes,  ink- 
ing rollers,  farm  machinery,  poles, 
masts  and  much  else  where  strength 
and  lightness  are  to  be  united.  Steel 


Handle-bar  of  bicycle 
in  steel-tubing. 


STRUCTURES  OF  STEEL  TUBING     41 


tubing  is  readily  bent  into  any  needed  contour,  even  when  of 
considerable  diameter.  Mr.  Egbert  P.  Watson  has  pointed 
out  its  availability  for 
highway  bridges  of  about 
forty  feet  span,  no  profes- 
sional bridge-builders  being 
needed  for  their  construc- 
tion. Near  Saxonville, 
Massachusetts,  a  pipe-arch 
bridge,  eighty  feet  long, 
provides  a  roadway  across 
the  Sudbury  River,  while 
carrying  within  its  pipe  a 
stream  which  forms  part  of 
the  Boston  water  system.  A 
bridge  of  similar  form,  200 
feet  long,  spans  Rock  Creek 

in  the  City  of  Washington.    The  Eads  bridge  crossing  the  Missis- 
sippi, at  St.  Louis,  employs  for  each  span  eight  steel  tubes  of  nine 
inches     exterior     diameter. 
Tubes  large  and  small  have 
been  strengthened  by  adopt- 
ing the  model  of  an  old- 
fashioned     fire-lighter,     or 
spill,  a  bit  of  paper  rolled  A  pneumatic  hammer,  steel  tubing, 

spirally  as  a  hollow  tube. 

Blow  sharply  into  it  and  you  but  tighten  its  joints.    In  like  man- 
ner tubes  and  pipes  of  metal  are  all  the  tighter  when  their  seams 


A  sulky  in  steel  tubing. 


Fishing-rod  in  steel  tubing. 


Bridge  of  steel  pipe. 


42 


FORM-ARCHES 


are  spiral  instead  of  longitudinal.  An  eager  quest  for  combined 
strength  and  lightness  in  the  bicycle  has  ended  in  the  choice  of 
tubes  spirally  welded. 


Arch  bridge  of  steel  pipe, 
Sudbury  River,  near  Saxondale,  Mass. 


Spiral  fire-lighter. 


Spiral  weld  steel  tube. 

When  builders  of  old  began  to  rear  masonry  they  repeated  in 
stone  or  brick  the  forms  they  had  constructed  in  wood.    Accord- 
ingly the  lintels  of  their  doors  and  windows 
Arches.  were  flat.    It  was  a  remarkable  step  in  advance 

when  the  arch  was  invented,  probably  by  a 
bricklayer,  spanning  widths  impossible  to  horizontal  structures. 
A  flat  course  of  stone  or  brick  presses  downward  only;  an  arch 
presses  sidewise  as  well  as  downward.  It  is  this  sidewise  thrust, 
calling  into  play  a  new  resource,  that  gives  the  arch  its  structural 
advantage.  In  modern  masonry  the  boldest  arch  is  that  of  the 
bridge  at  Plauen,  Germany,  with  its  span  of  295^  feet.  Of 


ARCHES  43 

pointed  arches  the  chief  sustain  the  walls  of  Gothic  cathedrals ;  it 


Longest  stone  arch  in  the  world,  Plauen,  Germany. 

was  to  counteract  the  outward  thrust  of  these  arches  that  ex- 
ternal buttresses  were  reared, 
either  solid,  as  at  St.  Remy  in 
Rheims,  or  flying,  as  at  Notre 
Dame  in  Paris.  The  Saracenic 
arch,  offering  more  than  half 
of  a  circle,  is  not  so  strong  as 
the  Roman  arch,  but  it  has  a 
grace  of  its  own,  fully  re- 
vealed in  the  Alhambra,  and 
in  the  incomparable  mosque 
at  Cordova.  A  chain  of  small 
links,  a  watch-chain,  for  ex- 
ample, freely  hanging  between 
two  points  of  support  strikes 
out  a  catenary  curve ;  this  Ga- 
lileo suggested  as  the  outline 
for  an  arch  in  equilibrium;  it 
is  adopted  for  suspension 
bridges. 

"The  arch,"  says  Mr.  Wil- 
liam   P.    P.    Longfellow    in 
"The  Column  and  the  Arch,"    Church  of  St.  Remy,  Rheims,  France, 
was    the    great    constructive         Section  across  buttressed  choir, 
factor  in  the  architecture  of 

the  Roman  Empire;  it  added  enormously  to  the  builder's  re- 
sources in  planning,  and  to  his  means  of  architectural  effect. 


44  FORM-ARCHES 

It  gave  him  the  means  of  spanning  wide  openings,  and 
when  expanded  into  the  vault,  of  covering  great  spaces ;  it 
habituated  him  to  curved  lines  and  surfaces.  Helped  by  it,  and 


Curve  of  suspended  chain. 

spurred  by  the  new  wants  of  the  complex  Roman  civilization,  he 
enlarged  the  scale  of  his  buildings  and  greatly  increased  the  in- 
tricacy of  their  plans.  He  used  his  new  combinations  with  a  bold- 
ness and  fertility  of  invention  that  have  been  the  wonder  of  the 
world  from  that  age  to  ours,  constructing  on  a  scale  that  dwarfed 


Dam  across  Bear  Valley,  San  Bernardino  County,  California. 


ARCHES  45 

everything  that  had  gone  before  except  the  colossal  buildings  01 
Egypt.  Under  a  new  stimulus,  and  with  new  means  of  effect* 
Roman  building  greatly  outstripped  that  of  the  Greeks  in  extent, 
in  variety,  and  magnificence." 

An  arch  built  on  its  side,  with  its  convexity  upstream,  and  its 
ends  braced  against  rocky  banks,  serves  admirably  as  a  dam.  It 
has  in  many  cases  withstood  floods  much  higher  than  those  ex- 
pected by  its  designers.  Such  dams  must  not  be  too  long,  or 
what  is  saved  in  thickness  is  more  than  lost  in  length.  Arches 
inverted  are  used  in  many  places  as  gulleys  for  drainage.  Near 
Bristol,  in  England,  they  anchor  the  cables  of  the  Clifton  Sus- 
pension Bridge,  at  a  depth  of  eighty-two  feet  below  the  surface 
of  the  ground.  Many  tunnels  finished  in  masonry  have  outlines 
which  are  two  arches  united,  the  lower  arch  being  inverted.  The 
Cloaca  Maxima,  the  famous  sewer  at  Rome,  is  of  this  pattern; 
it  is  twenty-six  feet  high,  sixteen  feet  broad,  and  is  now  in  its 
twenty-fifth  century  of  service. 

From  arches,  built  of  parts  of  circles,  let  us  pass  to  the  circle 
itself,  and  glance  at  the  use  of  tubes  of  circular  section  as  we  be- 
gin to  consider  how  resistances  to  motion  may 
be  minimized.    The  use  of  the  bamboo  not  only  circles  and  Ot^er 
for  building,  but  for  the  carriage  of  water,  be- 
gan in  the  remote  past.    As  structural  material  it  was  light  and 
strong  as  we  have  noticed ;  laid  upon  the  ground  it  was  a  ready- 
made  water  pipe  of  excellent  form.   When 
trees  were  hollowed  out  to  convey  water, 
when   clay  was   modeled   into  tubes,   the 
hollow   cylindrical   shape   of   the   bamboo 
was  in  the  mind  of  the  Asiatic  artisan,  to 
be  faithfully  copied.     That  form  has  de- 
scended to  all  modern  piping  for  water, 
steam,  and  gas,  because  the  best  that  a 

pipe  can  take.     No  other  shape  hasj  pro- 

.   ,  ...  .f.,  %  Ferguson  locking-bar 

portionately  to  capacity,  so  little  surface         pipe     £ast  Jersey 

for  friction  inside  or  rust  outside.   A  lock-  pipe  Co.,  Pater- 

ing-bar   water   pipe,    devised   by   Mephan  son,  N.  J. 

Ferguson,  of  Perth,  Australia,  is  made  of 
two  plates  of  equal  width,  curved  into 
semi-circles  which  are  pressed  at  their  ends  into  channel  bars  of 


46  FORM-ELLIPTICAL  COVERS 

soft  steel.  As  the  locking-bars  and  joints  are  opposite  each  other, 
their  joints  can  be  tightly  closed  by  a  simple  machine  which  exerts 
pressure  in  a  straight  line.  This  construction  may  be  used  not 
only  for  pipes,  but  for  hydraulic  cylinders,  air  receivers,  mud  and 
steam  drums,  tubular  boilers  and  boiler  shells  where  high  pres- 
sures are  to  be  withstood. 

A  steam  boiler  or  other  vessel  under  severe  internal  strains  had 
best  be  spherical  if  equality  to  resistance  is  particularly  de- 
sired. Usually  a  cylindrical  shape  is  much  more  convenient,  and 
no  other  is  given  to  simple  steam  boilers  or  to  the  tubes  of  water- 
tube  or  fire-tube  boilers.  Tubes  comparatively  narrow,  are  readily 
manufactured  without  seam,  so  that  they  may  be  quite  safe  though 
thin ;  large  boilers  of  plates  riveted  together,  must  be  built  of  thick 
metal.  It  was  estimated  by  Mr.  F.  Reuleaux,  the  eminent  en- 
gineer, that  if  such  boilers  could  be  made  in  one  continuous  piece 
of  metal  by  the  Mannesmann  process,  so  successful  in  tube-mak- 
ing, an  economy  in  weight  of  at  least  one  third  would  be  feasible. 

In  water-tube  boilers  a  gainful 
departure  from  the  circular  form  in 
a  detail  of  their  design  is  worthy  of 
notice.  In  order  that  their  tubes 
may  be  kept  sound  and  clean  they 
are  rendered  accessible  by  hand- 
holes  which  pierce  the  front  and 
back  of  the  boiler.  Usually  these 
hand-holes  and  their  covers  are 
round,  a  form  which  makes  it  neces- 
sary to  put  the  cover  outside  the 
boiler  where  even  a  good  joint,  well 
stayed,  may  leak  or  give  way  under 
a  pressure  which  tends  to  force 
apart  the  cover  and  its  seat.  In 
the  Erie  City  boiler  the  covers  are 
elliptical ;  they  are  readily  passed 

Hand-hole  plates.  through  the  hand-holes  so  as  to  rest 

Erie  City  water-tube  boiler.  not  on  the  outside,  but  on  the  inside, 

of  the  boiler,  where  the  steam  pres- 
sure makes  their  joints  all  the  tighter.    A  further  advantage  is 


WHEELS  AND  BEARINGS  47 

that  each  elliptical  plate  is  large  enough  to  give  access  to  two 
tubes  instead  of  one,  lessening  the  lines  of  juncture  along  which 
leakage  may  occur. 

It  was  a  memorable  day  when  first  a  round  log  or  stick  was 
thrust  under  a  burden,  easing  its  motion  and  leading  to  the  wheel 
1  v  piecemeal  improvements.    A  section  cut  off 
from  the  end  of  a  round  log  is  to-day  the  wheel  Wheels, 

for  ox-carts  in  China  and  India.    In  its  crudest 
form  a  roller  enables  a  man  to  drag  a  load  instead  of  carrying  it, 
and  he  can  readily  drag  much  more  than  he  can  carry.     Wheel- 


Bullock  cart  with  solid  wheels. 

wrights  of  old  soon  found  that  a  wheel  need  not  be  solid,  that 
strong  spokes,  a  sound  rim,  and  a  metal  tire  embody  the  utmost 
strength  and  lightness.  Roller  and  ball  bearings  much  extend 
the  benefits  of  simple  wheels;  they  lessen  friction  in  the  best 
typewriters,  bicycles,  and  elevators;  in  wagons,  carriages,  and 
automobiles  roller  bearings  are  so  helpful  that  their  use  should  be 
universal .  Of  notable  efficiency  is  the  Hyatt  bearing,  formed  by 
winding  a  steel  strip  into  a  spiral  roller.  This  device  has  a  flex- 
ibility which  enables  it  to  conform  to  irregularities  of  motion 
much  better  than  can  a  solid  cylinder. 

For  machinery  the  wheel  is  indispensable.  The  hand  does  its 
work  chiefly  in  moving  to  and  fro,  as  in  sawing  and  whittling. 
Machines  outdo  manual  toil  by  moving  swiftly  and  continuously 


48 


FORM-BEARINGS 


in  a  circle :  instead  of  the 
smoothing  iron  we  have  the 
mangle,  boards  are  planed 
by  rotary  knives,  timber  is 
divided  by  circular  saws, 
and  the  steam  turbine  is 
displacing  the  steam  engine 
which  every  moment  has  to 
check  the  momentum  of 
huge  reciprocating  masses. 
Noteworthy  in  this  regard 
is  the  perfecting  press 
which  prints  a  newspaper 
from  a  continuous  roll,  as 
contrasted  with  the  old 
machine  which  demanded 
for  each  impression  a  dis- 
tinct series  of  to  and  fro 
movements.  .  The  Harris 
Rotary  Press  for  job  print- 
ing is  of  like  model.  It 
feeds  itself  with  6,500 
sheets  an  hour,  printing 
from  a  stereotype  or  an 
•  electrotype  curved  upon  its 
cylinder.  The  lathe,  simple 
enough  a  century  ago,  has 
been  developed  into  mach- 
ines of  great  complexity, 
power,  and  variety,  all  with 
the  original  rotary  mandrel 
as  their  essential  feature. 
Milling  machines,  steadily 
gaining  more  and  more 
importance,  employ  rotary 
cutters  which  dispense  with 
the  manual  chipping  and  filing  of  former  days. 

Wood  as  commonly  hewn,  sawn,  and  planed ;  bricks  as  usually 


Secti'on-A  B 

Ball  thrust  collar  bearing. 

Ball  Bearing  Co., 

Philadelphia. 


Rigid  bearings  for  driving  axles 

of  automobiles. 
Ball  Bearing  Co.,  Philadelphia. 


CURVES  AT  JOINTS 


49 


Hyatt  helical  roller  b 


Hyatt  rollers  supporting  an  axle. 

molded ;  stone  as  it  leaves  an  ordinary  hammer,  all  have  flat  sides 
and  square  edges.    Hence  it  has  been  easiest  to 
build   walls   and   floors   which    meet   at    right    Angles  Replaced 
angles,  and  to  leave  sharp  corners  on  outer         by  Curves. 
walls,  windows,  doorways,  and  chimneys.   This 
is  being  changed  for 
the    better;    in    stair- 
cases   the   boards    on 
which    we   tread   and 
those  which  join  them 
together  now  meet  in 
smooth  curves ;  so  do 
the  walls  of  rooms  as 
they     reach     ceilings 
and  floors,  conducing 
to  ease  and  thorough- 
ness in  sweeping  and 
cleansing.      In    outer 
walls,     in     doorways 
and  windows,  similar 
curves  reduce  liability 


Treads  and  risers  joined  by  curves. 


30  FORM- CURVES  REPLACE  ANGLES 


to  hurt  and  harm.  A  wagon  wheel  easily  knocks  pieces  from  an 
angle  of  brickwork;  it  makes  little  impression  on  bricks  retiring 
from  the  street  line  in  a  sweeping  curve,  as  in  the  Madison 
Square  Garden,  New  York.  Factory  chimneys  have  long  been 

built  round  instead  of  square; 
to-day  in  the  best  designs  the 
ducts  to  a  chimney  are  also 
freely  curved.  In  blast  fur- 
naces this  is  the  rule  for  every 
part  of  the  structure,  ensuring 
gain  in  strength,  lessening  re- 
sistance to  the  flow  of  gases, 
and  thus  saving  much  fuel. 
When  waterpipes  varying  in 


diameter  are  joined,  the  junc- 
tion should  be  a  gradual  curve, 
otherwise  retarding  eddies 
will  arise,  wasting  a  good  deal 
of  energy;  the  same  precau- 


Corner  Madison  Square  Garden, 
Madison  Avenue  and  26th  Street, 
New  York. 


Two  pipes  with  funnel-shaped  junction. 


tion  is  advisable  in  laying  pipes  for  steam  or  gas.    The  elbows  of 
pipes  for  gas,  steam  or  water  exert  the  least  possible  friction  when 

given  the  utmost  feasible 
radius.  All  the  various 
parts  of  heavy  guns  are 
curved,  since  any  sharpness 
of  angle  at  a  joint  brings  in 
a  hazard  of  rupture  under 
the  tremendous  strains  of 
explosion. 

Embossing  and  stamping  machines  may  either  decorate  a  sheet 
of  note  paper  or  make  a  tub  from  a  plate  of  steel.  Whatever  their 
size  these  machines  have  the  edges  of  their  dies  nicely  rounded, 
so  as  to  avoid  tearing  the  material  they  fashion.  To  ensure  the 
utmost  strength  in  the  machines  themselves  they  are  contoured  in 
ample  curves.  In  hydraulic  presses,  subjected  to  strains  vastly 
greater,  the  same  shaping  is  imperative,  otherwise  a  cylinder  may 
part  abruptly  with  disastrous  effect.  So,  too,  in  the  manufacture 
of  magnets  and  electro-magnets,  their  terminals  are  well  rounded 


CURVES  OF  A  WARSHIP  51 

to  ensure  the  closest  possible  approach  to  uniformity  of  field  and 
of  working  effect. 

A  glance  at  a  warship  discovers  her  varied  use  of  curves  in  de- 
fence ;  to  deflect  assailing  shot  and  shell,  her  plates  are  given 
bulging  lines,  her  turrets  are  built  in  spherical  contours,  and  her 
casemates  are  convex  throughout.  On  much  the  same  principle 
fortifications  are  rendered  bomb-proof,  or  rather  bomb-shedding; 
while  outworks  are  so  inclined  that  bombs  fall  to  distances  at 
which  they  do  little  or  no  harm.  As  in  war  so  in  peace ;  there  is 
gain  in  building  breakwaters  with  an  easy  curve;  to  give  their 
masonry  and  timbers  a  perpendicular  face  would  be  to  invite 
damage,  whereas  a  flowing  contour  like  that  of  a  shelving  beach, 
slows  down  an  advancing  breaker  and  checks  its  shock.  In  rear- 
ing lighthouses  to  bear  the  brunt  of  ocean  storms  the  outline  of  a 
breakwater  is  repeated  to  the  utmost  degree  feasible.  Often,  how- 
ever, the  base  supporting  a  lighthouse  is  too  small  in  area  for  such 
an  outline  to  be  possible. 


CHAPTER  V 

FORM-Continued.    SHIPS 

Ships  have  their  resistances  separately  studied  .  .  .  This  leads  to  improve- 
ments of  form  either  for  speed  or  for  carrying  capacity  .  .  .  Experiments 
with  models  in  basins  .  .  .  The  Viking  ship,  a  thousand  years  old,  of 
admirable  design  .  .  .  Clipper  ships  and  modern  steamers.  Judgment 
in  design. 

,  ,  ! 

IN  giving  form  to  a  ship  a  designer  has  a  three-fold  aim, — 
strength,  carrying  capacity  and  speed.     Strength  is  a  matter 
of  interior  build  as  much  as  of  external  walls ;  it  is  conferred  by 
girders,  stays  and  stiffeners  which  we  have  already  considered, 
so  that  we  may  here  pass  to  the  general  form 
Forms  of  Ships      of  the  hull>  which  decides  how  much  freight  a 
Adapted  to  Special      ,  .  ,  ,    .  . 

Resistances  P  ma^  carrv>  ancl  to  a  cel"tam  extent,  how 

fast  she  may  run.  A  ship  is  the  supreme 
example  of  form  adapted  to  minimize  resistance  to  motion;  its 
lesson  in  that  regard  will  be  the  chief  theme  of  this  chapter.  Un- 
til the  close  of  the  eighteenth  century  the  resistance  to  the  progress 
of  a  ship  was  regarded  as  a  single,  uncompounded  element,  plainly 
enough  varying  with  the  vessel's  speed  and  size.  It  was  Marc 
Beaufoy,  who  first  in  1793  in  London,  pointed  out  that  a  ship's 
resistance  has  two  distinct  components;  first,  friction  af  the  shell 
or. skin  with  the  water  through  which  the  vessel  moves,  dependent 
upon  the  area  of  that  skin;  second,  resistance  due  to  the  forma- 
tion of  waves  as  the  ship  advances,  dependent  upon  the  speed  of 
the  vessel  and  the  shape  of  her  hull.  Other  resistances  have  since 
been  detected,  but  these  two  are  much  the  most  important  of  all ; 
each  varies  independently  of  the  other  as  one  ship  differs  from 
another  in  form,  or  as  in  the  same  ship  one  speed  is  compared  with 
another.  To  take  a  simple  case :  a  ship's  model  of  a  certain  form, 
of  perfectly  clean  skin,  is  towed  at  various  speeds  and  the  pull  of 
the  tow-line  is  noted;  then  the  same  model  with  its  skin  rough- 


SHIP  RESISTANCES  VARY  53 

ened  and  covered  with  marine  growths  is  towed  at  the  same 
speeds,  and  much  greater  pulls  are  observed  in  the  tow-line.  The 
wetted  surface  is  the  same  in  the  two  series  of  experiments,  the 
speeds  correspond  throughout,  and  the  increase  of  resistance  due 
to  a  roughening  of  surface  can  only  mean  that  the  friction  be- 
tween the  water  and  the  submerged  skin  has  increased.  Next  we 
take  a  model  of  certain  form  and  definite  size,  and  a  second  model 
having  the  same  area  of  wetted  surface  but  a  different  form ; 
we  tow  both  models  at  the  same  speed  to  find  that  one  requires  a 
decidedly  stronger  pull  than  the  other.  This  difference  cannot 
be  due  to  frictional  resistance  of  surface,  for  this  is  the  same  in 
both  models,  therefore  it  must  be  due  to  the  increased  resistance 
offered  by  the  water  as  it  is  pushed  aside,  a  resistance  measurable 
in  the  created  waves.  Mr.  Edmund  Froude,  an  eminent  English 
authority,  says : 

"For  a  ship  A,  of  the  ocean  mail  steamer  type,  300  feet  long 
and  31^2  feet  beam  and  2,634  tons  displacement,  going  at  13 
knots  an  hour,  the  skin  resistance  is  5.8  tons,  and  the  wave  re- 
sistance 3.2  tons,  making  a  total  of  9  tons.  At  14  knots  the  skin 
resistance  is  but  little  increased,  namely  6.6  tons ;  while  the  wave 
resistance  is  nearly  double,  namely,  6.15  tons.  Mark  how  great, 
relatively  to  the  skin  resistancej  is  the  wave  resistance  at  the 
moderate  speed  of  14  knots  for  a  ship  of  this  size  and  of  2,634 
tons  weight  or  displacement.  In  the  case  of  another  ship  B,  300 
feet  long,  46.3  feet  beam,  and  3,626  tons  displacement— a  broader 
and  larger  ship  with  no  parallel  middle  body,  but  with  fine  lines 
swelling  out  gradually— the  wave  resistance  is  much  more 
favorable.1  At  13  knots  the  skin  resistance  is  rather  more  than 
in  the  case  of  the  other  ship,  being  6.95  tons  as  against  5.8  tons; 
while  the.  wave  resistance  is  only  2.45  tons  as  against  3.2  tons. 
At  14  knots  there  is  a  very  remarkable  result  in  this  broader  ship 

1  The  entrance  is  that  part  of  the  ship  forward  where,  it  enters  the  water 
and  swells  out  to  the  full  breadth  of  the  ship;  the  run  is  the  after  part 
from  where  the  ship  begins  to  narrow  and  extending  to  the  stern.  A 
ship  may  consist  of  only  entrance  and  run;  it  may  have  a  middle  body 
of  parallel  sides  between  the  entrance  and  run.  Such  a  middle  body  is 
discussed  by  Lord  Kelvin  in  "Popular  Lectures  and  Addresses,"  Vol.  Ill, 
Navigation,  p.  492. 


54  FORM- SHIPS 

with  its  fine  lines,  all  entrance  and  run  and  no  parallel  middle 
body :— at  14  knots  the  skin  resistance  is  8  tons  as  against  6.6 
tons  in  ship  A,  while  the  wave  resistance  is  only  3.15  tons  as  com- 
pared with  6.15  tons.  The  two  resistances  added  together  are 
for  B  only  11.15  tons,  while  for  A,  a  smaller  ship,  they  amount  to 
12.75  tons." 

These  figures  show  that  a  designer  must  bear  in  mind  the  speed 
at  which  this  ship  is  to  run;  they  prove  that  he  may  choose  one 
form  to  minimize  friction,  or  another  form  if 
he  particularly  wishes  to  bring  wave-making 
resistance  to  the  lowest  possible  point.  Forms 
of  these  two  kinds  are  readily  studied  when  represented  in  models 
12  to  20  feet  in  length  towed  through  tanks  built  for  the  purpose. 
Experiments  of  this  kind  were  undertaken  as  long  ago  as  1770,  in 
the  Paris  Military  School;  the  methods  then  inaugurated  and 
copied  in  London  at  the  Greenland  Docks  were  greatly  improved 
by  Mr.  William  Froude  in  a  tank  which  he  constructed  at  Tor- 
quay in  England,  in  1870.  His  modes  of  investigation,  duly 
adopted  by  the  British  Admiralty,  and  after  his  death  continued 
by  his  son,  Mr.  Edmund  Froude,  have  created  a  new  era  in  ship 
design.  To-day  in  Europe  and  America  there  are  eleven  such 
tanks  as  Mr.  Froude's,  all  larger  than  his  and  more  elaborate  in. 
their  appliances.  In  addition  to  learning  the  behavior  of  models 
diverse  in  type,  Mr.  Froude  worked  out  the  rules  which  subsist 
between  the  performance  of  a  model  and  that  of  a  ship  of  like 
form;  these  he  brought  to  proof  in  1871  when  he  towed  Her 
Majesty's  Ship  Greyhound,  and  verified  his  estimates  in  towing 
its  model.  The  rules  concerned,  known  as  those  of  mechanical 
similitude,  are  given  in  detail  by  Professor  Cecil  H.  Peabody  in 
his  "Naval  Architecture,"  page  410.  While  experiments  become 
more  and  more  valuable  as  one  refinement  succeeds  another,  there 
is  always  much  well  worth  knowing  to  be  learned  from  the  actual 
behavior  of  a  vessel  as  she  takes  her  way  through  a  canal,  a  shal- 
low river,  or  the  storm-beaten  stretches  of  the  sea. 

The  experimental  tank  of  the  United  States  Navy  at  Washing- 
ton, is  470  feet  long,  44  broad,  and  14^2  deep;  it  is  arranged 
for  models  20  feet  in  length.  See  the  page  opposite.  The 
towing  carriage  is  a  bridge  spanning  the  tank  just  above  the 


A  VIKING  SHIP  55 

water;  it  is  a  riveted  steel  girder.  The  towing  mechanism,  of 
massive  proportions,  is  driven  by  four  electric  motors  of  abundant 
power.  A  double  set  of  brakes  brings  the  carriage  gradually  and 
quietly  to  rest  from  a  high  speed.  A  self-acting  recorder  meas- 
ures both  speed  and  resistance.  Ship  builders  may  have  models 
built  by  the  Bureau  in  charge,  that  of  Construction  and  Repair 
of  the  United  States  Navy  Department,  and  have  these  models 
towed  at  any  desired  speeds,  paying  simple  cost. 

It  was  in  1880  that  the  lessons  of  towing  experiments  with 
models  began  to  be  adopted  in  practice.  As  a  result  the  forms 
of  steamers  have  been  greatly  improved.  Originally  their  lines 
were  taken  from  those  of  sailing  vessels  but,  as  dimensions  grew 
bolder  and  speeds  were  increased,  it  became  clear  that  steamers 
demanded  wholly  different  lines  of  their  own.  These  lines,  for- 
tunately, may  be  plainly  disclosed  in  experiments  with  a  model, 
because  a  steamer  usually  runs  on  an  even  keel,  in  which  position 
a  model  is  easily  driven  through  a  tank.  A  sailing  vessel,  on  the 
contrary,  is  nearly  always  heeled  over  by  the  wind  so  that  it  sel- 
dom runs  on  an  even  keel ;  tank  experiments,  therefore,  avail  but 
little  for  the  improvement  of  its  lines.  Even  were  the  model  in- 
clined at  various  angles  in  one  test  after  another,  sails  must  be 
omitted,  with  their  influence  on  steering,  their  lifting  and  bury- 
ing effects,  often  extreme. 

A  thousand  years  ago  the  Vikings  of  Norway  roved  the  seas 
in  boats  of  a  form  which  is  admired  to-day.    To  those  hardy  ad- 
venturers swiftness  and   seaworthiness  meant 
nothing  less  than  life  and  victory,  their  eyes    A  Viking  Ship  a 
perforce  were  keen  to  note  what  craft  sped  USoid 

fastest  through  the  water,  what  new  curves 
kept  waves  from  coming  aboard.  Perchance  as  they  refined  upon 
keel  and  rib  they  took  golden  hints  from  the  shapes  of  gulls  and 
fish.  To  be  sure,  long  before  science  was  dreamt  of,  they  had  to 
work  by  rule-of-thumb,  but  the  thumb  was  joined  to  brains  that 
did  honor  to  human  nature.  On  page  56  is  illustrated  the  Viking 
Ship  unearthed  early  in  1880  at  Godstad,  near  Sandef  jord  in  Nor- 
way, in  a  mound  where,  according  to  tradition,  a  king  and  his 
treasure  had  been  buried.  It  is  the  most  complete  and  the  best 
oreserved  vessel  of  ancient  date  in  existence.  It  is  fullv  described 


A  FAMOUS  CLIPPER  57 

and  pictured  in  "The  Viking  Ship,"  by  Mr.  N.  Nicolaysen,  a 
work  published  in  1882  by  Mr.  Albert  Cammermeyer,  Christiania. 
Mr.  Nicolaysen  regards  the  vessel  as  having  been  built  about  A.  D. 
900,  for  use  in  war  by  the  great  chieftain  whose  tomb  it  be- 
came. The  ship  was  65  feet,  10  inches  long,  on  the  keel;  with 
an  extreme  length  over  all  of  78  feet,  I  inch ;  amidships  it  was 
16  feet,  9  inches;  its  depth  amidships  from  the  top  of  the  bul- 
warks to  the  keel  was  3  feet,  11%  inches.  The  material  through- 
out was  pine.  The  helm,  a  plank  shaped  like  a  broad  oar,  was 
fastened  to  the  side  of  the  vessel.  In  accordance  with  the  number 
of  its  oars  and  shields  this  ship  must  have  had  a  crew  of  sixty- 
four,  besides  these  came  the  steersman,  the  chieftain  and  prob- 
ably a  few  more  of  his  companions,  making  a  total,  in  all  likeli- 
hood, of  seventy  to  be  carried  by  her.  Says  Mr.  Nicolaysen :  "In 
the  opinion  of  experts  this  must  be  deemed  a  masterpiece  of  its 
kind,  not  to  be  surpassed  by  aught  which  the  shipbuilding  craft 
of  the  present  age  could  produce.  Doubtless,  in  the  ratio  of  our 
present  ideas,  this  is  rather  a  boat  than  a  ship ;  nevertheless  in  its 
symmetrical  proportions,  and  the  eminent  beauty  of  its  lines,  is 
exhibited  a  perfection  never  attained  until  after  a  long  and  dreary 
period  of  clumsy  unshapeliness,  when  it  was  once  more  revived 
in  the  clipper-built  craft  of  the  nineteenth  century."1 

Thirty  to  sixty  years  ago  much  of  the  world's  commerce  was 
borne  by  clipper  ships.     In  all  likelihood  as  good  lines  as  ever 
went  into  a  vessel  of  this  kind  were  displayed 
in  the  Young  America,  outlined  on  page  58,  flipper  SWp»  and 
.     .,    .        0        ,        ,      s*\*t        .  T     »•      Modern  Steamers. 

built  in  1853  for  the  California  and  East  India 

trade.  She  once  ran  from  New  York  to  San  Francisco  in  103 
days,  and  from  San  Francisco  to  New  York  in  63  days,  records 
which  have  never  been  excelled.  Her  deck  length  was  235  feet ; 
her  depth  of  hold  25  feet,  9  inches;  her  moulded  beam  was  40 
feet,  2  inches;  her  displacement  was  2,713  tons.  The  lines 
worthiest  of  remark  in  her  design  are  the  diagonals  and  buttocks, 
together  with  her  easy  entrance  and  run.  Most  clipper  ships  were 
fuller  forward  than  aft ;  this  had  two  advantages :  first,  when 
forward  burdens,  anchors  and  the  like,  tended  to  an  undue  settling 

1  A  detailed  description  of  the  Viking  Ship  is  given  in  the  "Transactions 
of  the  Institute  of  Naval  Architects"  (London),  Vol.  XII,  p.  298. 


AN  OCEAN  GREYHOUND  59 

down  at  the  head,  it  was  well  to  increase  the  buoyancy  forward ; 
second,  towing  experiments  prove  that  a  form  slightly  fuller  for- 
ward than  aft  offers  less  resistance  than  the  reverse.  This  shape 
was  hit  upon  by  the  old-time  designers,  doubtless  as  a  result  of 
many  a  shrewd  experiment. 

In  the  early  days  of  steamships,  hollow  or  somewhat  concave 
water  lines  forward  were  in  favor.  Experiments  with  models 
have  demonstrated  that  for  boats  so  full  in  section  as  to  be  nearly 
square,  it  is  best  to  have  forward  lines  which  are  straight  or  nearly 
so.  Recently  it  has  been  shown  that  at  high  speeds,  with  a  mid- 
ship section  nearly  semicircular,  resistance  is  a  little  lessened 
by  very  slightly  hollowing  the  water  lines  forward. 

If  a  steamer  is  to  have  the  utmost  speed,  as  the  Kaiser  Wil- 
helm  II,  outlined  on  page  60,  her  design  will  be  very  unlike  that 
of  a  vessel  required  to  carry  as  much  cargo  as  possible  at  a 
moderate  or  low  speed,  as  in  the  case  of  the  steamship  sketched 
on  page  61.  The  dimensions  of  the  Kaiser  Wilhelm  II  are: 
—length  over  all,  7063/2  feet;  beam,  72  feet;  depth,  29  feet,  6j4 
inches;  displacement,  29,000  tons;  speed,  2^/2  knots;  indicated 
horse  power,  38,000.  As  we  compare  with  her  details  of  form 
the  general  features  of  our  cargo  carrier,  page  61,  we  observe  in 
this  freighter  the  full  form  of  its  water  lines,  its  almost  straight 
and  blunt  entrance  forward;  we  also  notice  that  the  lower  part 
of  the  bow  has  been  cut  away  to  avoid  a  reversal  of  curves  which 
would  create  an  eddy  with  its  consequent  increase  of  resistance. 
Further  we  may  remark  the  squareness  of  the  midship  section, 
which  means  carrying  capacity  at  its  maximum,  together  with 
the  long  parallel  middle  body,  little  resisted  by  the  water,  ending 
aft  in  buttocks  and  water-lines  quickly  turned.  This  is  a  twin- 
screw  ship:  of  length  358  feet,  2  inches;  beam,  46  feet;  draft, 
23  feet ;  depth  from  shelter  deck,  34  feet,  8  inches ;  displacement, 
8,270  tons ;  speed,  9  to  10  knots. 

A  good  designer  has  an  easy  task  in  drawing  lines  for  a 
freighter  in  which  the  weight  of  hull,  machinery  and  coals  may 
be  only  40  per  cent,  of  the  displacement,  leaving  60  per  cent,  for 
earning  space.  Contrast  this  with  an  Atlantic  flyer,  where  but 
5  per  cent,  may  remain  for  cargo.  Here  the  designer's  problems 
are  difficult  indeed,  and  the  chief  way  out  of  them  is  to  enlarge 


60 


61 


62 


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JUDGMENT  IN  SHIP  DESIGN 


63 


his  ship  as  much  as  he  dares,  for  the  bigger  his  vessel,  its  form 
and  speed  unchanged,  the  less  will  be  its  resistance  as  compared 
with  displacement.  But  to  an  increase  of  size  there  are  hard  and 
fast  bounds ;  first,  those  imposed  by  the  shallowness  of  channels 
and  harbors ;  while  the  depth  of  a  ship  is  thus  restricted,  its  length 
,  may  be  somewhat  extended  with  safety  and  gain ;  to  increase  of 
beam  there  are  distinct  and  moderate  limits,  to  overpass  them 
means  that  the  ship  will  follow  the  wave  contour  of  a  heavy  sea 
so  closely  as  to  have  a  quick,  jerky  and  dangerous  motion. 

To  design  a  ship  in  this  case  and  every  other  is  plainly  a  matter 

of  compromise,  a  quest  of  the  optimum  by  a  balancing  of  demands 

for  safety,  strength,  speed,  capacity,  handiness, 

judgment  in  Ship          d  behavior  in  a  Sea-wav,  so  that  each  in- 

Design. 

vested  dollar  may  in  the  long  run  earn  the 
largest  return  possible.  Excellent  examples  of  judicious  design  are 
the  best  passenger  steamers  plying  between  Europe  and  New  York. 
Usually  their  section  amidships  is  like  that  of  a  cargo  vessel,  but 
for  a  special  reason.  Within  the  freighter's  walls  the  greatest 
feasible  cross-section  must  be  created,  so  that  the  shape  is  box- 
like;  in  a  high-speed  passenger  ship  the  form  is  also  square,  be- 
cause harbors  are  shallow;  were  they  less  shallow  the  designer 


Cross-sections  of  ships 


64  FORM- SHIPS 

would  choose  a  midship  section  somewhat  semicircular  in  con- 
tour. Were  our  harbors  deepened,  the  easy  sections  of  the  first 
transatlantic  steamers  could  be  repeated  in  their  gigantic  suc- 
cessors of  to-day,  with  increased  speed  for  each  horse  power 
employed. 

What  a  designer  can  do  when  his  aim  is  swiftness  at  the  ex- 
pense of  all  other  considerations,  is  shown  in  the  lines  of  the 
torpedo-boat  destroyer,  page  62.  Its  length  over  all  is  246  feet; 
length  at  water  level,  240  feet,  10  inches ;  beam,  22  feet,  3  inches ; 
mean  draft,  6  feet,  iJ/£  inches;  displacement,  489  tons;  speed, 
30  knots.  It  is  interesting  to  contrast,  on  page  63,  the  cross-sec- 
tion amidships  of  this  vessel,  with  similar  lines  of  three  other 
typical  vessels  described  in  this  chapter.1 


*In  writing  these  pages  on  the  forms  of  ships  I  have  been  much  in- 
debted to  Mr.  Harold  A.  Everett,  Instructor  in  Naval  Architecture, 
Massachusetts  Institute  of  Technology,  Boston.  G.  I. 


CHAPTER  VI 

FORM-Continued.    SHAPES  TO  LESSEN  RESISTANCE 
TO   MOTION 

Shot  formed  to  move  swiftly  through  the  air  ...  Railroad  trains  and 
automobiles  of  somewhat  similar  shape  .  .  .  Toothed  wheels,  conveyors, 
propellers  and  turbines  all  so  curved  as  to  move  with  utmost  freedom. 

WHILE  ships  are  much  the  largest  structures  built  for 
motion,  and  therefore  meet  resistances  which  the  designer 
must  lessen  as  best  he  may,  other  moving  bodies,  small  as  com- 
pared with  ships,  encounter  resistances  so  extreme  that  their  re- 
duction enlists  the  utmost  skill  and  the  most 
careful  study.  Speeds  vastly  higher  than  those  Projectiles  and 
of  ships  are  given  to  projectiles.  A  ball  leav- 
ing  a  gun  muzzle  with  a  velocity  of  3,410  feet 
a  second,  as  at  Sandy  Hook  in  January,  1906,  suffers  great  at- 
mospheric resistance,  overcome  in  part  by  the  shot  having  a 
tapering  or  conoidal  form.  Indians  long  ago  stuck  feathers 
obliquely  into  arrows  so  as  to  keep  flight  true  to  its  aim  by  giving 
shafts  a  spiral  motion ;  an  attendant  advantage  being  to  lengthen 
flight.  The  same  principle  appears  in  rifling,  that  is,  in  cutting 
spiral  grooves  in  the  barrels  of  firearms  large  and  small,  a  mis- 
sile receiving  a  spinning  motion  through  its  base,  a  thin  pro- 
truding disk  of  soft  metal,  forced  into  the  grooves  by  the  ex- 
plosive. At  first  the  grooves  in  firearms  were  straight  with  in- 
tent to  preclude  fouling;  spiral  grooves  were  introduced  by 
Koster  of  Birmingham  about  1620.  Delvigne,  a  Frenchman,  de- 
vised a  lengthened  bullet  narrower  than  the  bore  so  as  to  enter 
freely,  under  the  pressure  of  firing  it  completely  filled  the  bore, 
rotating  with  great  velocity  as  it  sped  forth. 

65 


66      FORMS  TO  LESSEN  RESISTANCE 

Now  that  railroad  speeds  are  approaching  those  of  projectiles, 
the  outlines  of  trains  are  resembling  those  of  shot  and  shell.  In 
the  experiments  with  very  fast  trains  at  Zossen,  in  Germany, 
October,  1903,  each  car  had  a  paraboloidal  front,  much  diminish- 


Racing  automobile.    Wedge  front  and  spokeless  wheels. 


ing  the  resistance  of  the  air.  Racing  automobiles  are  usually  en- 
cased in  a  pointed  shell  which  parts  the  air  like  a  wedge;  their 
wheels,  too,  are  supported  not  by  spokes,  but  by  disks  having  no 
projections.  As  electric  traction  becomes  more  and  more  rapid 
in  its  interurban  services,  the  cars  will  undoubtedly  be  shaped  to 
lessen  atmospheric  resistance.  Especially  is  this  desirable  in  a 
tunnel  service,  such  as  that  of  the  New  York  Subway,  where  the 
resistances  are  extreme  for  the  same  reason  that  a  boat  in  a  canal 
is  harder  to  draw  than  if  in  water  both  broad  and  deep.  Just  as 
in  ship-design,  it  is  in  sharpening  the  front  and  rear  of  a  car  or 
a  train  that  most  economy  is  feasible ;  the  friction  at  the  sides  can- 
not be  much  lessened  except,  in  the  case  of  a  train,  by  joining 
each  car  to  the  next  by  a  vestibule  such  as  that  of  the  Pullman 
Company. 
Electric  traction  finds  gain  in  a  track  having  in  places  a  decided 


GEARING  AND  CONVEYORS 


67 


inclination.  In  the  monorail  line  between  Liverpool  and  Man- 
chester a  downward  dip  in  the  line  at  each  terminal  quickens  de- 
parture, and  in  arrival  aids  the  brakes  by  checking  speed  on  the 
up-grade.  In  the  swift  motion  of  ordinary  machinery  the  resist- 
ance of  the  air  is  a  source  of  considerable  loss.  By  encasing  a 
heavy  flywheel  in  sheet  iron  so  as  to  present  a  smooth  surface  to 
the  atmosphere,  M.  Ingliss  has  saved  4.8  per  cent,  of  the  energy 
of  a  630  horse  power  engine. 

In  the  simplest  machines  motion  may  be  transmitted  by  wheels 
in  contact,  faced  with  adhesive  leather,  rubber,  or  cloth.  Teeth, 
however,  are  usually  employed ;  as  wear  takes 

place  they  permit  a  little  plav,  a  slight  loose-          Gearing: 

Conveyors. 

ness,  which  contact  wheels  altogether  refuse. 
Toothed  wheels  have  the  further  advantage  that  they  do  not  slip, 
their  motion  is  positive.     How  teeth  may  best  be  contoured  in- 
volves nice  questions  in  geom- 
etry.     They    should    always 
push   and    never   grind    each 
other,  and  should  move  with 
the  least  possible  friction.    In 
some    ingenious    designs    the 
teeth    of    any    one    particular 
wheel  of  a  series  will  enmesh 
with  the  teeth  of  any  other 
wheel,  no  matter  how  much 
larger  or  smaller.  Bevel  gears 
cut  by  Mr.  Hugo  Bilgram,  of 
Philadelphia,  turn  with  hardly 
any     friction     whatever,     al- 
though   in    some    wheels    the 
teeth  run  askew,  or  are  sec- 
tions of  cones  which  do  not 
meet  at  their  apices.    The  Bil- 
gram gear  cutter,  and  the  Fellows'  gear  shaper  which  turns  out 
plain  gear,  exert  a  to  and  fro  planing  action.    Ordinary  gears  arc 
cut  on  milling  machines  by  rotary  cutters,  or  may  be  manufactured 
on  a  Bliss  press  without  cutting  the  original  lines  of  fibre.    The 
importance  of  accurate  and  easy-running  gears  increases  steadily; 


Bilgram  skew  gearing. 


68     FORMS  TO  LESSEN  RESISTANCE 

they  are,  for  example,  applied  to  steam  turbines  whose  velocib 
must  be  reduced  in  the  actuation  of  ordinary  machines.     Auto- 


Grain  elevator. 

mobiles  and  bicycles  also  demand  reducing  gear  running  with 
the  utmost  freedom. 


Robins  conveying  belt  of  rubber  moved  on  rollers. 


PROPELLERS 


69 


Ewart  detachable  link  belting. 


The  grain  elevator,  invented  many  years  ago,  is  the  parent  of 
manifold  conveyors  of  coal,  lime,  ore  or  aught  else.  Their  re- 
ceivers have  links  shaped  so  as  to  extend  for  hundreds  of  feet 
as  continuous  belts.  Link  belting  may  be  had  in  detachable  sec- 
tions, fitting  each  other  at  secure  hinges  which  allow  free  motion. 

The  Augustin  B.  Wolvin,.  a  typical  ore-carrier  on  the  great 
lakes,  is  56  feet  in  depth ; 
its  hold  is  curved  to  allow  a 
clam-shaped  bucket  to  seize 
ten  tons  of  ore  at  each  dip. 
It  is  probable  that  at  no 
distant  day  rapid  transit  in 
cities  will  employ  contin- 
uous moving  platforms, 
just  as  conveyors  and  tel- 
pherage systems  are  taking 
the  place  of  the  discontin- 
uous transport  of  grain, 
coal,  cotton,  ore,  and  heavy  merchandise. 

The  screw,  an  inclined  plane  wound  about  an  axis,  forms  the 
propeller  for  steamships  and  many  steamboats.    There  is  a  good 
deal  of  debate  as  to  the  principles  which  should 
decide  its  best  lines.     Here  evidently  is  a  field        Propellers. 
which    will    handsomely    repay    thorough    in- 
vestigation.    The  power  expended  in  steamships,  whether  fast 
or  slow,  is  prodigious;  any  marked  improvement  in  the  contour 
of  screws  will  mean  either  a  saving  of  fuel  or  an  increase  of 
speed.    Of  equal  importance  with  water-propulsion  is  the  setting 
in  motion  of  air.    In  blast  furnaces  enormous  volumes  of  air  are 
forced  at  high  pressure  into  the  fuel  and  ore:  the  fans  are  care- 
fully molded  in  screw  form,  any  departure  from  the  best  curves 
entailing  serious  loss.    Fans  for  less  important  services  are  seldom 
shaped  with  care  and  usually  waste  much  energy. 

Allied  to  screws  are  turbine  wheels,  much  the  most  efficient  of 
water  motors.    The  shaping  of  their  vanes  as  volutes  minimizes 
the  loss  of  energy  in  shock  as  the  water  comes 
in,  and  lessens  to  the  utmost  the  velocity  of         Turbines, 
the  stream  as  it  leaves  the  wheel.     Now  that 


70      FORMS  TO  LESSEN  RESISTANCE 


steam  turbines  are  scoring  a  success  both  on  land  and  sea  the 
contouring  of  their  vanes  with  extreme  nicety  is  an  important 

problem  of  the  engineer.  A 
perfected  form  means  the 
highest  economy. 

It  is  interesting  to  note 
how  the  screw  propeller,  the 
fan,  and  the  turbine  wheel 
have  each  led  to  a  converse 
invention.  Mr.  Edwin  Rey- 
nolds, of  Milwaukee,  has 
devised  a  pump  in  screw 
form  of  capital  efficiency 
under  low  heads.  The  fan 
has  long  had  its  converse 
in  the  windmill,  now  more 
popular  throughout  Amer- 
ica than  ever  before,  mainly 

,    ;  ^  because   shaped   with   new 

I   ^«r.        ',  /        1(14'"'      \  excellence.       In     the    best 


Curves  of  turbines. 
Niagara  Power  Co. 


models,  built  of  steel,  the 
sails  are  each  a  section  of  a 
volute  carefully  designed 
to  discharge  the  wind 

evenly,  just  as  in  the  parallel  case  of  emission  from  a  water 
mover,  such  as  the  Worthington  pump.  This  capital  pump  is 
simply  a  turbine  wheel  reversed.  Its  impeller  and  diffusion  vanes 
take  up  water  from  rest,  lift  it  to  a  height  which  may  be  as  much 
as  2,000  feet,  and  then  deliver  it  at  rest,  with  little  loss  from  in- 
ternal eddies  or  slippage. 


Steel  vanes  of  wind-mill. 
Fairbanks,  Morse  &  Co.,  Chicago. 


PELTON  WHEEL 


71 


The  Pelton  wheel,  pre-eminent  among  water-motors  of  the 
impulse  type,  owes  its  economy  chiefly  to  each  bucket  being 
divided  in  halves  and  curved  with  the  utmost  nicety. 


Jet  for  Pelton  wheel. 


CHAPTER  VII 

FORM-Continued.    LIGHT  ECONOMIZED  BY  RIGHTLY  SHAPED 
GLASS.    HEAT    SAVED    BY    WELL    DESIGNED 
CONVEYORS  AND  RADIATORS 

Why  rough  glass  may  be  better  than  smooth  .  .  .  Light  is  directed  in 
useful  paths  by  prisms  .  .  .  The  magic  of  total  reflection  is  turned  to 
account  .  .  .  Holophane  globes  .  .  .  Prisms  in  binocular  glasses  .  .  . 
Lens  grinding  .  .  .  Radiation  of  heat  promoted  or  prevented  at  will. 

THESE  are  times  when  an  inheritance,  such  as  the  window 
pane,  venerable  though  it  be,  is  freely  criticized  and  shown 
to  be  far  from  perfect.  We  find,  indeed,  that  surfaces  and  forms 
long  given  to  the  glass  through  which  light  passes,  or  from  which 
light  is  reflected,  are  faulty  and  wasteful.  This 
A.  Shrewd  Observer  means  that  sunshine  can  be  turned  to  better  ac- 
Improves  Windows  count  than  ever  before,  that  artificial  light  can 
be  employed  with  an  economy  wholly  new.  A 
few  years  ago  when  we  provided  a  window  with  plate  glass, 
smooth  enough  for  a  mirror,  nothing  better  seemed  possible. 
Thanks  to  the  late  Edward  Atkinson,  of  Boston,  we  know  to-day 
that  in  many  cases  glass  may  be  too  smooth  to  give  us  the  best 
service,  that  often  we  may  get  much  more  light  from  panes  of 
rough,  cheap  make  than  from  costly  plate  glass.  He  tells  us : 
"In  1883,  when  I  inspected  a  large  number  of  English  cotton 
•mills,  I  found  them  glazed  with  rough  glass  of  rather  poor  qual- 
ity, the  common  glass  of  England  being  inferior  to  our  own  from 
the  general  lack  of  good  sand.  On  asking  why  rough  glass  was 
used  instead  of  smooth  I  was  told  that  rough  glass  gave  a  uniform 
and  better  light.  To  my  astonishment  I  found  this  true.  The 
interior  of  a  mill  so  lighted  had  the  aspect  of  diffused  illumination. 
This  led  me  to  reason  on  the  subject.  I  looked  into  the  construc- 
tion of  the  Fresnel  lens,  in  which  a  combination  of  lenses  and 
curved  surfaces  concentrates  rays  of  light  into  a  single  far  reach- 

72 


GLASS  OF  NEW  EFFICIENCY          73 

ing  beam.  I  reasoned  that  if  one  set  of  angles  or  curves  could 
thus  concentrate  light,  then  by  reversal  of  such  angles  or  sur- 
faces, light  could  be  diffused." 

Mr.  Atkinson  proceeded  to  gather  specimens  of  glass  not  only 
of  common  rough  surface,  but  also  in  ribbed  and  prismatic 
forms.  These  he  handed  for  examination  and  comparison  to 
Professor  Charles  L.  Norton  of  the  Massachusetts  Institute  of 
Technology,  Boston.  His  report  says :  "The  hopelessness  of 
trying  to  get  something  for  nothing,  that  is,  to  get  a  sheet  of 
window  glass  to  throw  into  a  room  more  light  than  fell  upon  it, 
appeared  so  plain  to  me  that  I  made  all  my  preparations  to  meas- 
ure not  a  gain  but  a  loss  of  light  in  using  Mr.  Atkinson's  samples. 
The  results  of  the  tests  may  be  briefly  stated :  In  a  room  thirty 
feet  or  more  deep  we  may  increase  the  light  to  from  three  to  fif- 
teen times  its  present  effect  by  using  'Factory  Ribbed'  glass  in- 
stead of  plane  glass  in  the  upper  sash.  By  using  prisms  we  may, 
under  certain  conditions,  increase  the  effective  light  to  fifty  times 
its  present  strength.  The  gain  in  effective  light  on  substituting 
ribbed  glass  or  prisms  for  plane  glass  is  much  greater  when  the 
sky-angle  is  small,  as  in  the  case  of  windows  opening  upon  light 
shafts  or  narrow  alleys.  With  the  use  of  prisms  a  desk  fifty  feet 
from  a  window  has  been  better  lighted  than  when  but  twenty  feet 
from  the  same  window  fitted  with  plane  glass.  .  .  .  'Ribbed' 
and  'Maze'  glass  are  of  very  great  value  in  softening  the  light, 
especially  when  windows  are  directly  exposed  to  the  sun,  aside 
from  their  effectiveness  in  strengthening  the  light  at  distant 
points.  With  the  'Maze'  glass  the  artist  may  have,  in  all  weathers 
and  in  all  directions,  what  is  in  effect  a  much-desired  north  light. 
The  same  glass  provides  the  photographer  with  light  as  well 
diffused  as  when  cloth  screens  or  shades  are  employed  and  of 
much  greater  intensity." 

Plate  prism  glass  is  now  manufactured  with  its  outer  or  street 
surface  ground  and  polished  like  plate  glass,  with  its  prisms  ac- 
curate and  smooth.  In  dimensions  which  may  reach  fifty-four  by 
sixty  inches  it  affords  surfaces  easily  kept  clean,  and  transmitting 
much  more  light  than  glass  held  in  frames  of  small  divisions. 

WThence  the  gain  in  thus  exchanging  plane  glass  for  glass 
rough,  ribbed,  or  prismatic  ?  Rays  streaming  through  an  ordinary 


74 


FORM— GLASS 


window  strike  nearby  surfaces  of  wall,  ceiling,  and  floor;  from 
these  they  are  reflected  in  large  measure  and  return  through  the 

glass  to  outer  space. 
Rough,  ribbed,  or  prismatic 
glass  throws  the  rays  much 
further  into  the  room,  hence 
they  strike  so  much  larger 
an  area  of  wall,  ceiling,  and 
floor  that  in  being  reflected 
again  and  again  the  light 
is  well  diffused,  and  but  lit- 
tle is  sent  forth  again  into 
outside  space.  The  form 
of  the  glass  gives  the  enter- 
ing light  its  most  useful  di- 
rection, so  that  the  new 
Luxfer  prism.  panes  serve  better  than  the 

old.      This    effect    is    most 

striking  when  prisms  are  carefully  adapted  to  a  particular  case  in 
both  their  angles  and  their  placing.  In  traversing  glass,  light  is 
absorbed  and  wasted,  so  that  the  shorter  its  path  the  better.  In 


Fresnel  lens. 

the  compound  lens  devised  in  1822  for  lighthouses  by  Augustin 
Jean  Fresnel,  light  is  as  effectively  bent  by  the  part  of  the  glass 
shown  in  dark  lines  as  if  the  whole  lens  were  employed. 

This  brings  us  to  means  for  the  best  use  of  artificial  light. 
Within  the  past  thirty  years  the  standard  of  illumination,  thanks 
to  electricity,  has  steadily  risen.  More  important  than  ever,  there- 
fore, is  it  that  light  should  be  employed  pleasantly  and  effectively. 
This  in  the  main  is  a  question  of  placing  the  sources  of  light 
judiciously,  and  of  so  reflecting  and  refracting  their  rays  that 
they  will  be  of  agreeable  quality,  and  arrive  where  they  are 


REFLECTORS 


wanted  with  the  least  possible  loss.  Reflectors  rightly  shaped  and 
kept  clean  economize  much  light.  For  lack  of  them  in  streets  and 
squares  we  may  sometimes  observe  half  the  rays  from  a  lamp 
taking  their  way  to  the  sky  where  they  do  no  good.  In  shop  win- 
dows ribbed  reflectors  throw  full  illumination  on  the  wares  dis- 
played, while  the  sources  of  light 
are  out  of  view.  The  same  method 
is  employed  in  art  galleries 
and  in  museums.  A  parabolic 
reflector  sends  forth  as  parallel 
rays  the  powerful  beam  of  a  light- 
house, a  locomotive,  or  a  search- 
light. An  incandescent  lamp  of  in- 
genious design  is  silvered  on  its 
upper  half  so  that  none  of  its  light 
is  wasted.  Because  the  arc  lamp  is 
the  cheapest  of  all  illuminants  it  is 

adopted  for  out-of-door  lighting  where  its  unpleasant  glare  is  tem- 
pered by  distance.  In  factory  lighting  its  brightness  is  excessive  and 


Lamp  and  reflector  a  unit. 


Inverted  arc-light 


re  FORM— GLASS 

harmful  unless  moderated.  A  capital  plan  is  to  employ  an  ordinary 
continuous  current  and  place  the  positive  carbon,  with  its  brilliant 
centre,  below  the  negative  carbon;  beneath  these  two  carbons  a 
good  reflector  throws  the  rays  to  the  ceiling,  whence  they  descend 
with  agreeable  diffusion  and  much  less  loss  than  when  globes  of 
ground  glass  surround  the  arc.  A  common  white  ceiling  when 
quite  flat  is  an  excellent  reflector ;  indeed,  a  sheet  of  white  blotting 
paper  returns  light  nearly  as  well  as  a  polished  mirror,  and  for 
many  purposes  it  serves  better ;  the  mirror  sends  back  its  beam  in  a 
sharply  defined  area  which  may  be  dazzling,  the  paper  scatters 
light  with  thorough  and  agreeable  effect. 

Usually  a  mirror  is  a  sheet  of  highly  polished  metal,  or  a  plate 
of  glass  with  a  quicksilver  backing;  preferable  to  either  is  clear 
glass,  all  by  itself,  so  formed  as  totally  to  reflect  an  impinging 
beam  of  light.  To  understand  the  principle  involved  in  its  use  we 
will  for  a  little  while  bid  good-by  to  lamps  of  all  kinds. 

A  hall  of  delights  is  the  New  York  Aquarium,  in  the  historic 
Castle  Garden  at  the  Battery.  Its  tanks  display  a  varied  and 

..>*'-  superb  collection  of  fish,  whose  beauty  of  form 

Delight  and  Gain  and  color  heightened  by  swift  and  graceful 

as  We  Watch  a     motion,   fascinates  the  eye  as  no  museum  of 

Fish  in  Water,  dead  things,  however  splendid,  ever  does.  When 
a  tank  is  still,  or  nearly  still,  and  a  gold-fish  or 
a  perch  is  quietly  resting  near  the  surface  of  the  water,  one  may 
see  its  form  reflected  from  that  surface  as  perfectly  as  if  by  a 
mirror.  The  point  of  view  must  be  close  to  the  tank,  with  the  eye 
somewhat  lower  than  the  fish.  So  perfect,  at  times,  is  this  mir- 
roring that  young  folks  are  apt  to  suppose  the  reflection  to  be 
a  second  fish,  and  they  are  puzzled  to  remark  how  strangely  it 
resembles  its  mate  just  below.  What  explains  this  reflection?  A 
ray  of  light  can  always  pass  from  a  rare  medium,  such  as  air,  into 
a  dense  medium,  such  as  water,  because  it  is  bent  toward  their 
common  perpendicular.  But  a  ray  cannot  always  pass  from  a 
dense  into  a  rare  medium,  from,  let  us  say,  water  into  air,  for  if 
the  ray  were  to  be  bent  away  from  the  common  perpendicular 
more  than  90°  it  would  altogether  fail  to  emerge  from  the  water. 
No  luminous  ray  can  pass  from  water  into  air  if  it  makes  a 
greater  angle  with  the  perpendicular  than  48°  35'.  Suppose  AB 


TOTAL  REFLECTION 


77 


(page  78)  to  be  the  water  level  of  a  tank.  A  ray  leaving  F  will  be 
bent  so  as  to  reach  C,  a  ray  from  G  will  reach  D,  a  ray  from  H 
will  reach  E ;  but  a  ray  from  L  will  be  bent  so  much  as  to  pass 
along  the  surface  of  the  water  as  OB,  and  a  ray  from  I  will  be 
bent  so  as  to  return  beneath  the  surface  of  the  water  to  I.  Rays 


Sacramento  perch  totally  reflected  in  aquarium. 
A,  surface  of  water. 


such  as  I,  undergoing  total  reflection,  afford  us  our  second  image 
of  a  fish  at  rest  near  the  surface  of  water :  to  observe  this  kind  of 
image  we  need  not  journey  to  the  New  York  Aquarium;  with 
patience  we  may  behold  it  in  a  small  home  aquarium  with  flat 
sides  of  clear  glass,  waiting  until  the  water  is  quiet  and  a  fish 
comes  close  to  the  surface. 

Every  dense  transparent  substance  has  this  ability  to  yield 
images  by  total  reflection,  each  substance  having  a  critical  angle 
of  its  own ;  we  have  just  seen  that  for  water  this  angle  is  48°  35'. 
Glass  is  made  in  many  varieties,  each  with  a  special  critical  angle, 
never  much  different  from  that  of  water.  A  right-angled  prism 


78 


FORM— GLASS 


of  glass,  which  any  optician  can  supply,  serves  as  a  capital  mirror 
for  rays  striking  its  surface  at  ninety  degrees.     Such  prisms  are 


AB  water  level.    F,  G,  H,  L  are  refracted  to  C,  D,  E,  B. 
I  is  totally  reflected  to  I. 

employed  in  opera  glasses,  in  hand  telescopes,  in  reflectors  for 
light-houses,  and  in  the  Holophane  globes  we  are  about  to 
examine.  The  efficiency  of  these  prisms  may  be  as  much  as  92 
per  cent.,  whereas  that  of  the  best  silvered  mirrors  never  exceeds 
90  per  cent.  The  loss  in  a  prism  is  due  to  a  slight  reflection  by 
the  surface  on  which  the  rays  first  fall,  and  by  the  absorption  of 
light  in  the  glass  itself ;  this  second  loss,  of  course,  increases  with 
the  thickness  of  the  prism. 

Now  that  we  understand  the  principle  of  total  reflection,  let  us 

see  how  it  is  applied  to  increasing  the  effectiveness  of  a  Wels- 

bach  mantle  or  an  electric  lamp.    And  first  let 

Total  Reflection  in"s  say  that  we  m^  wish  HSht  UP°"  a  SIm11 
Artificial  Lighting: area,  mainly  in  a  single  direction,  as  downward 

Holophane  Globes,  upon  a  desk  or  reading-chair.     Or,  in  a  quite 

different  manner,  if  we  are  to  illuminate  a  wide 

space  such  as  that  of  a  large  parlor.     These  requirements  are 

fulfilled  by  the  Holophane  globes,  devised  by  M.  Blondel  and  M. 


HOLOPHANE  GLOBES 


79 


135* 


Psaroudaki,  which  are  made  in  many  shapes,  each  adapted  to  a 
specific  duty.  The  upper 
half  of  each  globe  is 
formed  into  prisms  of  such 
angles  that,  zone  by  zone, 
the  glass  totally  reflects  im- 
pinging rays  in  just  the  di- 
rections desired.  The  con- 
touring is  accurate  to  the 
thousandth  part  of  an  inch. 
With  this  thorough  reflec- 
tion is  combined  diffusion 
as  thorough,  the  interior  of 
the  globe  being  shaped  as 
ribs.  Thus,  with  the  least 
possible  waste,  the  upper  Holophane  globe,  vertical  section, 

half  of  the  source  of  light 

is  utilized.    What  of  the  lower  half  ?    Its  rays  pass  through  prisms 
formed  so  as  to  refract  impinging  light  into  desired  paths  with 


B 


Section  of  Holophane  globe. 

Ray  A  is  refracted  as  A',  C  as  C.    B,  totally  reflected,  then  re- 
fracted, emerges  as  B'.    D  takes  a  similar  course, 
emerging   as   D'. 


80 


FORM— GLASS 


but  little  loss.  As  a  whole,  therefore,  these  globes  furnish  a  beau- 
tiful means  of  illumination  with  all  but  perfect  economy,  special 
forms  of  them  sending  light  in  any  direction  desired. 


Diffusing  curves. 

Holophane  globe.  Rays  are  split 

into  b,  e,  reflected,  then  as  e, 

f,  g,  refracted;  and 

into    b,  c,  d, 

refracted. 


Class  A,  Class  B, 

Holophane  globe,  throw-  rays  mainly  directed 
ing  rays  mainly  down-      at  an  angle  of  60°. 
ward. 


Class  C, 

casting  rays  chiefly  in  a 
lateral  direction. 


BINOCULAR  GLASSES 


81 


Section  of  Holophane  globe  and  Welsbach  mantle. 

showing  distribution  of  light. 
Each  typical  ray  as  refracted  is  marked  by  a  letter  of  its  own. 


In  the  Zeiss  Works  at  Jena,  in  Germany,  optical  instruments 
of  the  highest  excellence  are  manufactured ;  many  of  these  take 
advantage  of  the  principle  of  total  reflection  we 
have  been  considering.  When  the  task  was  Total  Reflection  in 
assumed  of  producing  a  new  and  improved  Binocular  Glasses, 
telescope,  it  was  observed  that  an  ordinary 
telescope,  built  up  of  lenses,  is  inconveniently  long  and  heavy  in 
comparison  with  its  magnifying  power.  The  question  arose 
whether  it  was  possible  to  construct  short  instruments  of  a  magni- 
fying power  of  four  to  twelve  diameters.  Porro,  an  Italian,  about 
the  middle  of  the  nineteenth 


c 


century  suggested  totally  re- 
flecting prisms  so  placed  that 
while  the  total  travel  of  a  ray 
would  be  the  same  as  in  an 
ordinary  telescope,  the  two 
ends  of  the  luminous  path  would  be  near  together,  while  the  whole 


How  a  wire  may  be  shortened  while 
its  original  direction  is  resumed. 


82 


FORM— GLASS 


would  be  more  effective  than  if  four  mirrors  were  employed. 

His  idea  may  be  repre- 
sented by  a  wire  one  meter 
long  so  bent  that  its  ends 
are  much  less  than  one 
meter  apart.  In  an  illus- 
tration of  a  field-glass  as 
manufactured  at  the  Zeiss 
Works,  on  the  Porro  prin- 
ciple, it  will  be  remarked 
that  the  entering-  ray 


Four  mirrors,  I,  2,  3,  4,  reflect  a  ray  in 
a  line  parallel  to  its  original  path. 


passes  through  lenses  which  are  farther  apart  than  the  lenses 
which  form  the  eye-pieces.     Thus  a  much  wider  field  is  viewed 


Prisms  for  Zeiss  binocular  glasses. 


than  that  of  an  ordinary  glass,  while  as  the  two  images  received 
from  the  two  eye-pieces  differ  more  than  those  observed  in  direct 
vision,  the  perception  of  depth  is  increased  in  a  notable  degree. 
This  construction  is  adapted  to  sporting,  marine,  and  opera- 
glasses,  as  well  as  to  field-glasses. 

Lenses  nevertheless  continue  to  be  much  more  important  than 
prisms,  and  the  proper  shaping  of  their  surfaces  involves  high 
reaches  of  both  science  and  art.  The  properties 
Lenses  Still          of  j^e  giass>  of  course,  count  for  most  in  pro- 
ducing combinations  free  from  color  for  tele- 
scopes, microscopes,  and  cameras.     Jena  glass,  described  in  an- 
other chapter  of  this  book,  with  its  extraordinary  range  of  re- 
fractive and  dispersive  qualities  has  brought  optical  instruments 


LENS-GRINDING 


83 


to  virtual  perfection.    Meanwhile  the  arts  of  lens-grinding  leave 
little  to  be  expected  in  the  way  of  future  improvement.     It  is 


Zeiss  binocular  glasses : 
longitudinal  and  cross-sections. 


The  Production 
of  Optical 
Surfaces. 


astonishing  that  a  lens  forty-two  inches  wide  can  be  so  truly 
curved  as  to  focus  the  image  of  a  star  as  an  immeasurable  dot. 

Let  us  look  at  some  of  the  instruments  designed  by  a  master  for 
shaping  glass  discs  into  lenses.  Some  of  the  best  telescopes 
in  existence  are  from  the  hands  of  Mr.  John 
A.  Brashear,  of  Allegheny,  Pennsylvania. 
The  grinding  tools  he  employs  he  has  con- 
toured in  such  wise  as  to  produce  desired 
curves  free  from  error.  The  first  polishers  are  of  the  ordinary 
form  with  square  or  circular  facets  equally  distributed  over  the 
surface  of  the  tool,  as  in  Figs.  H  and  8.  When  the  polish  is 
brought  to  its  best,  the  glass  is  allowed  to  cool  slowly  to  a  normal 
temperature,  and  is  then  carefully  studied  as  to  its  defects.  These 
are  removed  and  the  surfaces  finished  with  iron  tools,  of  the  same 
diameter  as  the  surface  to  be  worked,  each  tool  being  laid  off  into 


84  FORM— GLASS 

six  sections,  as  in  Figs.  3,  4,  5,  6,  7.  The  tool  being  warmed, 
pitch  is  spread  over  its  leaf-like  spaces,  which  are  given  the  proper 
curve  by  being  pressed  down  on  the  previously  wetted  concave 
surface ;  the  pitch  and  tool  are  next  quickly  cooled  with  water. 
In  the  shaping  of  these  spaces  rests  success.  The  zone,  a,  a,  in 
the  first  figure,  needing  the  greatest  amount  of  abrasion,  meets 


Tools  for  producing  optical  surfaces. 
John  A.  Brashear,  Allegheny,  Pa. 

the  widest  part  of  the  leaflet,  but  in  order  that  no  zonal  error  may 
be  introduced,  as  in  b,  c,  c,  b,  of  the  second  figure,  it  is  gently 
tapered  in  each  direction,  the  amount  of  taper  being  governed  by 
the  lateral  stroke  given  to  the  polisher,  as  well  as  by  the  amount 
of  departure  of  the  zone  from  the  normal  curve. 

But  after  all  the  astronomers  aided  by  lenses  thus  carefully 
shaped  are  few,  while  millions  of  people  suffer  from  defects  of 
sight  which  are  overcome  by  suitably  formed  spectacles. 


BI-FOCAL  LENSES 


85 


In  this  field  a  recent  minor  improvement  is  worthy  of  mention. 
Benjamin  Franklin  many  yeais  ago  made  a  pair  of  spectacles  in 
which  the  upper  half  of  each  glass  was  ground 
for  far  seeing,  the  lower  half  for  near  seeing. 
To-day  such  bi-focal  spectacles  are  not  made  in 
halves,  with  an  unpleasant  broken  line  across  them.  In  each  of 
the  new  eyeglasses  toward  the  base  a  small  lens  of  dense  quality 


Bi-focal 
Spectacles. 


BLADE 


COUNTERSUNK  BLA0C 


COMPLETED  L  f/VS 

Bi-focal  lens  for  spectacles. 


is  enclosed;  through  this  lens  a  wearer  looks  at  objects  nearby; 
through  the  upper  part  of  the  eyeglass  he  looks  at  distant  objects. 
The  joining  of  the  three  parts  is  effected  so  skilfully  as  not  to  be 
discernible. 

From  light  we  pass  to  its  twin  phase  of  energy,  heat,  for  a 
glance  at  the  forms  of  devices  which  enable  us  to  use  heat  with 
economy.  When  we  wish  a  furnace,  crucible, 
or  cooking  vessel  to  maintain  the  highest  pos- 
sible temperature,  we  give  it  as  little  surface 
as  possible.  On  the  contrary  when  a  warming  apparatus  is  de- 
vised, its  surface  is  freely  extended.  The  traditional  fireplace, 
for  all  its  cheerfulness,  yields  but  little  heat.  Benjamin  Franklin 


Economy 
of  Heat. 


86 


FORM-HEAT  RADIATION 


copied  its  form  in  the  stove  which  bears  his  name;  as  it  stands 
out  from  a  wall  it  warms  the  air  all  around  itself,  instead  of  on 

one  side  only.  This  model  is 
familiar  in  gas  stoves,  whose 
heat  thoroughly  radiated  and 
convected  far  exceeds  that  de- 
rived from  fireplaces.  In 
Canada  forty  years  ago  it  was 
usual,  especially  in  the  coun- 
try, to  set  up  gallows-pipes 
and  dumb-stoves,  or  drums, 
bulky,  hollow  structures  of 
sheet  iron,  which  obliged  the 
heated  products  of  combustion 
to  take  a  roundabout  course  as 
they  passed  to  the  chimney. 
To  be  sure  as  thus  cooled  the 
gases  were  less  effective  as 
draft  makers,  but  we  must  re- 
member that  one  of  the  most 
wasteful  uses  of  fire  is  in 
warming  air  or  other  gases 
for  the  sake  of  putting  them  in  motion.  In  modern  factories,  cen- 
tral lighting  stations,  and  the  like  huge  installations,  mechanical 
draft  sends  a  quick  current  through  a  short 
chimney,  saving  much  fuel.  Excellent  in  de- 
sign are  the  tile  stoves  of  Germany  and  Hol- 
land. Their  gentle  heat  does  not  parch  the 
air ;  in  moderately  cold  weather  they  render  it 
unnecessary  to  light  furnaces  which  develop, 
at  such  times,  unduly  high  temperatures. 

In  factories  the  heating  coils  filled  with 
steam  or  hot  water  were  at  first  fastened  to 
the  floor.  Then  came  attaching  them  to  the 
ceiling  whence  their  heat  is  gently  radiated ; 
on  the  floor  the  coils  may  gather  dust  and  dirt 
with  risk  of  fire ;  with  the  other  plan  there  is 
a  saving  of  floor  space,  and  accidental  leaks 
are  at  once  in  evidence. 


Canadian  box  stove  with  gallows-pipe. 


Canadian 
dumb-stove. 


RADIATORS 


87 


Tubes   for  warming  are   specially   effective   when   dented   or 
buckled  in  directions  at  right  angles  to  each  other  and  to  the  axis 


Tubing  for  radiator. 
Dalham  Works,  Manchester,  England. 


of  the  tube.  This  form  gives  the  heating  water  or  steam  a  swirl- 
ing motion  which  causes  it  to  part  more  rapidly  with  its  heat  than 
does  a  cylindrical  tube  of  the  same  surface.  Gold's  electric  heater 


Gold's  electric  heater. 

for  street-cars,  bath-rooms,  and  the  like,  is  a  spiral  of  resistant 
alloy,  hung  in  a  light  metallic  frame,  the  whole  presenting  a  large 
surface  to  the  air.  Automobiles  driven  by  heat  engines  require 


Stolp  wired  tube  for  automobiles. 

coils  of  the  utmost  possible  surface  whereat  cooling  can  take 
place;  in  many  cases  this  cooling  is  furthered  by  the  action  of  a 
quick  fan.  In  like  manner  the  condensers  of  steam-engines,  espe- 
cially aboard  ship,  are  made  up  of  slender  tubes  presenting  to 
the  steam  a  chilling  area  of  vast  extent. 


88 


FORM— BOILERS  AND  PIPES 


Inventors   have   long   addressed   themselves   to   the   difficulty 
caused  by  the  expansion  and  contraction  of  structures  as  tern- 


Corrugated  boiler. 

peratures  change.  For  years  the  cylindrical  fire-boxes  of  marine 
boilers  have  been  corrugated,  so  as  to  allow  them  a  certain  play 

without  breaking  from  their  fasten- 
ings, or  tearing  their  seams,  when 
heated  or  cooled.  This  form  is  adopted 
with  success  for  the  Morison  fire- 
boxes of  the  Vanderbilt  locomotives. 
In  quite  different  situations  metal 
piping,  in  a  length  of  let  us  say  100 
feet,  is  provided  against  trouble  from 
shrinkage  or  expansion  by  a  U  bend. 
When  the  diameter  of  the  pipe  is 
twelve  inches,  this  bend  is  usually 

about  ten  feet  in  extent ;  for  a  six  inch  pipe,  a  bend  six  feet  long 
suffices.  Another  difficulty  due  to  heat  is  the  limitation  of  speed 
imposed  by  the  heat  which  friction  creates.  A  new  type  of  cir- 
cular saw  has  a  hollow  arbor  through  which  flows  cold  water,  so 
that  motion  may  be  faster  than  ever  before.  The  same  arbor  ap- 
pears in  various  other  machines  with  like  advantage. 


Pipe  so  bent  as  to  permit 
contraction  or  expansion. 


CHAPTER  VIII 

FORU-Contin*ffd.    TOOLS  AND  IMPLEMENTS  SHAPED 
FOR  EFFICIENCY 

Edge  tools  old  and  new  .  .  .  Cutting  a  ring  is  easier  than  cutting  away 
a  whole  circle  .  .  .  Lathes,  planers,  shapers,  and  milling  machines  far 
outspeed  the  hand  .  .  .  Abrasive  wheels  and  presses  supersede  old 
appliances  .  .  .  Use  creates  beauty  .  .  .  Convenience  in  use  .  .  .  Ingenu- 
ity may  be  spurred  by  poverty  in  resources. 

WE  have  just  reviewed,  all  too  briefly,  how  light  and  heat  are 
economized  by  structures  of  judicious  form.     At  this  point 
we  will  bestow  a  rapid  glance  at  the  economy  of  work  as  promoted 
by  sound  design  in  tools  and  implements,  in  the  machines  which 
embody  these  for  tasks  far  beyond  the  personal 

skill  or   power   of  the   strongest  and   deftest          Tools  and 

.  r  Implements, 

mechanic. 

When  of  old  a  savage  took  up  a  stone  to  serve  as  a  rude  knife 
or  chisel,  we  may  be  sure  that  he  chose  the  sharpest  flint  he  could 
fin-d.  If  he  could  better  its  shape  by  knocking  it  into  something 
like  a  wedge,  what  task  was  easier  ?  Our  museums  display  an  im- 
mense variety  of  stone  hammers,  axes,  knives,  and  arrowheads, 
showing  how  art  long  ago  improved  the  forms  of  simple  tools  and 
weapons  offered  by  nature.  Modern  tools  and  weapons,  for  all 
their  immense  diversity,  were  every  one  prefigured  in  the  rude 
armory  of  primitive  man. 

Descended  from  his  flint  knife  is  the  abounding  variety  of  steel 
cutting  tools  all  the  way  from  the  razor,  concave  on  both  sides, 
to  the  axe,  doubly  convex.  As  the  arts  have  become  more  special- 
ized, as  artificial  power  has  been  introduced,  the  contrasts  of 
the  form  of  one  tool  with  another  have  grown  more  and  more 
striking.  The  bar  which  slices  metal  is  stout  of  build,  and  rec- 
tangular in  section,  while  a  lancet  is  little  wider  or  thicker  than  a 

89 


90 


FORM-TOOLS 


Carving  chisels  and  gouges. 


man  to  exert  great  leverage. 

formerly  more  in  use  than  to-day. 

with  gimlet  points  they  break  their  own  paths. 


blade  of  grass.  The  knives 
which  divide  leather,  rubber, 
and  rope,  differ  much  from 
one  another ;  the  knife  which 
separates  the  leaves  of  a 
book  serves  best  when  dull. 
Gouges  for  carving  are 
nicely  adapted  to  the  pro- 
files they  are  to  cut;  while 
the  exigencies  of  the  power- 
lathe  require  its  tools  to 
be  designed  of  particu- 
lar strength  and  rigidity. 
Among  revolving  hand-tools 
the  brace  is  the  most  im- 
portant, enabling  the  work- 
A  minor  tool,  the  gimlet,  was 
Now  that  screws  are  made 


J 


Lathe  cutters. 


Ratchet  bit  brace. 


RING  DRILLS 


91 


Eskimo  skin  scraper. 


Annular 
Drills. 


From  the  beginning  tool-makers  have  shown  skill  in  fitting  a 
tool  to  the  hand,  as  in  the  Eskimo  skin- 
scraper  ;  this  simple  adaptation  may 
have  arrived  in  copying  the  effect  of 
wear.  Other  good  hints  have  come 
from  observing  an  implement  after  its 
work  is  done.  At  the  places  where 
mud  clung  to  a  plowshare  the  plow- 
maker  was  long  ago  told  at  what  points 
to  raise  his  metal ;  conversely,  when  a 
cutter  of  any  kind  is  unduly  worn  at 
any  part  of  its  side,  there  the  metal 
asks  to  be  somewhat  narrowed  down. 

A  circle  of  say  two  feet  in  diameter,  may  be  readily  cut  from  a 
boiler  plate  by  two  cutters,  one  at  each  end  of  a  horizontal  bar, 
the  bar  being  supported  by  a  central  upright 
axis  receiving  the  motive  power.  Because  the 
cut  is  narrow,  but  little  metal  is  wasted  as  chips. 
A  cut  of  this  ring-shape  effects  a  desirable  saving  even  when  the 
circle  to  be  swept  is  but  an  inch  or  so  in  width  instead  of  several 

feet.  When  an  auger  takes 
its  way  through  a  plank  it 
removes  as  chips  all  the 
wood  within  the  circle  of 
its  range;  a  drill,  of  com- 
mon form,  as  it  pierces 
stone  or  metal  acts  in  a 
similar  manner.  Motive 
power  is  greatly  econo- 
mized when  a  drill  is  tubu- 
lar, with  the  further  ad- 
vantage that  within  the 
ring  cut  a  solid  cylinder  re- 
mains to  be  broken  off  at 
intervals  and  lifted  out,  its 
core  informing  to  the  en- 
gineer in  quest  of  bed-rock,  to  the  prospector  of  mines  or  oil- 


Double  tool  drill  cutting  boiler  plate. 


92 


FORM— DRILLS 


fields,  or  to  the  geologist  who  reads  at  a  glance  the  composition 
of  a  mineral,  the  forces  which  have  impressed  it  age  after  age. 
Such  drills,  set  with  bortz  diamonds,  have  accomplished  remark- 


Diamond 


A  common  drill  removes  a 
whole  circle  of  stone, 


A  ring  drill  removes  much  less 
stone  with  the  same  effect. 


able  feats.  In  boring  out  260  columns  surrounding  the  dome  of 
the  capitol  at  Springfield,  Illinois,  cores  22 ^4  inches  in  diameter 
were  removed  from  holes  24  inches  wide;  without  sacrifice  of 
strength  there  was  a  saving  in  weight  of  three-fifths.  At  the 


TWIST  DRILLS 


93 


Ellenwood  coal  mine,  Kingston,  Pennsylvania,  a  core  17  feet,  5 
inches  in  breadth  was  taken  from  a  bore  only  five  inches  wider. 
When  the  engineers  in  1896  were  planning  the  foundations  for 
the  Williamsburg  Bridge,  New  York,  the  deepest  of  their  22 
borings  was  112  feet  below  high  water.  Steel  drills  had  indicated 
bed-rock  12  to  20  feet  higher  than  was  the  actual  case;  the 
•diamond  drill  showed  the  supposed  bed-rock  to  be  merely  a  de- 
posit of  boulders.  No  other  known  means  could  have  accom- 
plished these  results.  In  the  same  way  steel  guns  of  large  calibre 
have  been  drilled  so  as  to  leave  a  core  of  much  value,  while  in  this 
as  in  all  other  such  tasks,  the  boring  demanded  less  energy  and 
proved  less  straining  than  if  all  the  metal  within  the  sweep  of  the 
drill  had  been  reduced  to  fragments.  All  these  tools  were  pre- 
figured in  a  simple  ring  drill  used  two  thousand  years  ago  on 
the  banks  of  the  Nile ;  hollow  reeds  were  employed,  with  sand  as 
a  cutter. 

Twist  drills  are  superseding  flat  drills  as  stronger  and  better  in 
every  way.    A  twist  drill  is  made  with  a  slight  taper  toward  the 
shank  end.    Its  cross-section  is 

Twist  Drills.  not  quite  round,  the  diameter 
being  reduced  from  a  short  dis- 
tance behind  the  cutting  edge,  so  as  to  diminish 
friction  and  give  the  sides  of  the  drill  as  much 
clearance  as  possible.  The  advanced  edges  of 
the  flutes  are  all  full  circle,  so  as  to  maintain  the 
diameter  of  the  drill  and  keep  the  tool  steady. 
The  advantage  of  the  twist  drill  is  that  its  cuttings 
find  free  egress,  while  it  always  runs  true,  with- 
out reforging  or  retempering.  The  cutting  edges 
are  usually  ground  to  an  angle  of  sixty  degrees 
to  the  center  line  of  the  drill ;  for  brass  work  the 
angle  should  be  fifty  degrees. 

The  manner  in  which  a  lathe  tool  cuts  metal  is  shown  in  an 
outline  which  represents  a  tool  feeding  a  cut  along  a  piece  of 
wrought  iron.     The  removed  metal,  in  its  di- 
ameter and  openness,  tells  the  expert  operator          Lathe  and 

.      .  Planer  Tools, 

both  the  quality  of  his  cutter  and  how  it  is 

being  affected  by  wear.     The  principal  consideration,  says  Mr. 


Twist  drill. 


94 


FORM— LATHES 


Joshua  Rose,  in  determining  the  proper  shape  of  a  cutting  tool, 
for  use  in  a  lathe  or  a  planer,  is  where  it  shall  have  the  rake,  or 


How  a  tool  cuts  metal. 
Beginning  a  second  cut. 

inclination,  to  make  it  keen  enough  to  cut  well,  and  yet  be  as 
s-trong  as  possible;  this  is  governed,  in  a  large  degree,  by  the 
nature  of  the  work. 

In  giving  form  to  wood  and  metal  cheaply  and  rapidly,  ma- 
chine-tools have  within  recent  years  risen  to  great  importance.   Of 
these  the  lathe  is  one  of  the  chief.     It  seems 
to  be  descended  from  the  bow  drill,  the  tool 
which  was  whirled  by  a  cord  wrapped  round  it, 
or  it  may  be,  that  under  another  sky,  the  lathe  was  derived  from 
the  potter's  wheel  whose  axle  was  changed  from  a  vertical  to  a 

horizontal  plane.  For  cen- 
turies all  lathes  had  their  cut- 
ting tools  simply  laid  on  a  bar, 
or  rest,  just  as  in  the  hand 
cutting  lathe  of  to-day.  While 
this  afforded  opportunity  to 
skill  it  did  not  lend  itself  to 
large  or  uniform  production. 
Henry  Maudslay,  about  a  cen- 
tury ago,  immensely  broad- 
ened the  machine  in  scope  by 
devising  the  slide  rest  which 
firmly  grasps  the  cutting  tool, 
and  automatically  moves  it  to- 


Dacotah  fire-drill. 


LATHES 


95 


ward  or  away  from  the  axis  of  the  work,  as  well  as  along  the  work 
in  any  desired  line.    This  device  is  equally  applicable  whether  in 


Lathe:  a,  work;  b,  tail-stock;  c,  hand-tool  rest;  d,  dead-centre; 
e,  live-centre;  f,  face-plate;  g,  live-spindle;  h,  dead-spindle;  k,  head- 
stock;  m,  cone-pulley;  n,  driving-pulley;  o,  belt;  p,  treadle;  r,  treadle- 
hook;  s,  shears;  t,  treadle-crank. 


turning  a  pencil  case,  the  granite  columns  for  a  cathedral,  or  the 
propeller-shaft  of  an  ocean  steamer. 

The  lathe  has  been  developed  in  many  ways  until  it  has  become 
one  of  the  most  complex  of  all  machines,  adapted  to  tasks  which 
even  twenty  years  ago  seemed  impossible.  Only  two  of  its  varieties 
can  here  be  noticed,  the  Bianchard  lathe  for  cutting  irregular 
forms,  and  the  turret  lathe.  An  illustration,  taken  from  an  old 
engraving  shows  the  Blanchard  lathe  as  originally  built  for  shoe- 


96 


FORM— LATHES 


lasts.  A  pattern-last  and  the  block  to  be  carved  are  fixed  on  the 
same  axis  and  are  revolved  by  a  pulley.  On  a  sliding  carriage 
are  fastened  pivots  from  which  are  freely  suspended  the  axles  of  a 


W 


Compound  slide  rest. 

C,  shears;  E,  tool  carriage;  H,  cross  slide;  K,  cross 
slide  handle ;  L,  cross  feed  handle ;  P,  tool  post ;  T,  tool ; 
D,  driver;  W,  work. 


Blanchard  Lathe. 

A,  frame;  B,  carriage;  C,  gun  stock;  D,  former;  E,  cutter- 
head  ;  F,  guide  wheel ;  G,  swinging  frame ;  H,  feed  motion ; 
K,  shaft  for  revolving  stock  and  former. 


TURRET  LATHES 


97 


cutting  wheel,  and  a  friction  wheel,  equal  in  diameter.  The  cutting 
wheel  turns  on  a  horizontal  axle,  and  bears  on  its  periphery  a  series 
of  cutters.  The  friction  wheel  is  in  contact  with  the  pattern-last 
and  presses  against  it  while  in  motion.  During  revolution,  the 
pattern,  irregular  in  its  surface,  causes  the  axis  to  approach  or 


Turret  lathe:  an  early  Brown  &  Sharpe  model. 

C,  carriage;   T,  turret;  L,  hand  lever;  F,  face  plate;   D,  jaw 

chuck;  E,  tool. 

recede  from  this  friction  wheel ;  the  cutting  wheel  in  its  corre- 
sponding motion  removes  wood  from  the  block  until  a  duplicate  of 
the  pattern  appears.     This  lathe  much  im- 
proved and  modified  now  turns  not  only 
gun-stocks,  axe-handles  and  the  like,  but  re- 
peats   elaborate    carvings    with    precision. 
Ornaments  for  Pullman  cars  are  produced 
by  this  machine. 

The  turret  lathe,  equally  ingenious,  has  a 
turret  or  capstan,  which  carries  let  us  say 
eight  different  tools,  one  on  each  of  its 
eight  faces.  In  its  turn  each  tool  operates 
on  the  work  in  its  forward  traverse ;  it  then 
retires  while  the  turret  automatically  moves 
through  one-eighth  of  a  circle,  when  the 
next  tool  emerges  for  its  task,  and  so  on.1 

Lathes  have  given  rise  to  planers,  now 
built  of  great  strength  and  in  highly  com- 

'The   turret   principle   is   embodied   in   drills   and   a  variety   of   other 
machines.    It  was  adopted  in  remarkable  fashion  by  John  Ericsson  in  his 


Turret  of  turret 

lathe.     Side 

view.  Top 

view. 


98          FORM— MILLING  MACHINES 

plicated  designs.  In  a  lathe  the  object  turns  upon  centers  against 
a  tool ;  a  planer  carries  its  tool  in  a  revolving  cylinder,  the  work 
being  fed  in  a  straight  line.  A  shaper,  with  much  the  same  essen- 
tial construction,  moves  along  its  work,  the  wood  or  metal  operated 
on  remaining  stationary.  With  a  planer  or  a  shaper  the  size  and 
uniformity  of  the  work  depend  upon  the  skill  of  the  operator.  The 
planer  has  led  to  the  invention  of  a  machine  which  dispenses  with 
this  skill.  Bramah,  in  1811,  employed  a  revolving  cutter  to  plane 
iron,  adapting  to  metal  the  familiar  mechanism  for  planing  wood. 
This  was  the  beginning  of  the  milling  machine,  now  so  remark- 
ably developed  and  improved.  A  skilled  mechanic  sets  the  ma- 
chine and  the  chucks  which  hold  the  work ;  an  unskilled  hand  can 
continue  the  operations,  his  products  being  uniformly  of  the  di- 
mensions and  forms  desired.  Intricate  shapes  are  easily  executed, 
quite  impracticable  on  any  other  machine.  At  first  the  revolving 
mechanism  and  its  cutters  were  a  single  piece  of  metal ;  to-day 
cutters  of  costly  quality  are  inserted  in  cheap  metal ;  these  in- 
serted cutters  when  worn  out  are  easily  replaced. 

Monitor,  launched  in  1862  for  service  in  the  Civil  War.  Because  this 
vessel  had  to  navigate  shallow  streams,  its  draft  was  limited  to  eleven 


Ericsson's  Monitor. 


feet  As  it  was  thus  impossible  to  carry  the  burden  of  armor  necessary 
to  protect  a  high-sided  vessel,  he  was  obliged  to  design  a  sunken  hull 
Guns  and  gunner  were  protected  within  a  covered  cylindrical  turret  which 
as  it  turned  on  its  vertical  axis,  delivered  an  all-round  fire  while  the 
Monitor  stood  still.  Ericsson's  original  turret,  and  its  later  modifications 
in  the  leading  navies  of  the  world,  are  described  in  the  Life  of  John 
Ericsson,  by  William  Conant  Church,  New  York,  Scribner,  1890. 


Iron  planer;  a,  b,  c,  d,  fixed  cutting  tools;  M,  moving  bed. 
Niles-Bement-Pond  Co.,  New  York. 


Iron  shaper:  a,  b,  fixed  cutting  tools.    K,  M,  traveling  bars. 
Niles-Bcment-Pond  Co.,  New  York. 


100         FORM— MILLING  MACHINES 


Milling  machine,  R.  K.  Le  B'.or.d  Machine  Tool  Co.,  Cincinnati. 
A,  table ;  B,  overhanging  arm ;  C,  cutters ;  D,  spindle ;  E,  feed  box. 

In  many  cases  the  milling  machine  ousts  the  planer  as  much 
more  economical.  At  the  shops  of  the  Taylor  Signal  Company, 
Buffalo,  a  miller  of  the  Cincinnati  Milling 
Machine  Company  does  nine- fold  as  much 
work  as  a  planer.  It  takes  a  first  cut  % 
inch  deep  across  a  full  width  of  12  inches, 
makes  60  revolutions  per  minute,  feeds  .075 
inch  per  turn,  giving  a  table  travel  of  4^2 
inches  per  minute,  with  an  accuracy  limit  of 
.001  inch. 

Now  for  a  glimpse  of  what  a  great  in- 
ventor had  to  suffer  because  he  lived  prior 
to  the  era  of  machine  tools,  before  the  days, 
indeed,  of  that  indispensable  organ  of  the 


Milling  cutters  with 

inserted  teeth. 

Cincinnati  Milling 

Machine  Co. 


GRINDING  101 

lathe,  its  slide  rest.    The  first  steam  engines  of  James  Watt,  built 
at  the   Soho  Works,  near  Birmingham,   are  thus   described  :— 
"A  cast  iron  cylinder,  over  18  inches 
in    diameter,    an    inch    thick    and 
weighing  half  a  ton,  not  perfect,  but 
without  any  gross  error  was  pro- 
cured, and  the  piston,  to  diminish 
friction  and  the  consequent  wear  of 
metal,  was  girt  with  a  brass  hoop 
two  inches  broad.    When  first  tried 
the  engine  goes  marvelously  bad ;  it         Milling  cutters  executing 
made  eight  strokes  per  minute ;  but  complex  curves. 

upon  Joseph's  endeavoring  to  mend  Brown  &  Shan>e, 

•/    •*  j      .-11  A    ?u  Providence,  R.  I. 

it,    it    stood    still;    and    that,    too, 

though  the  piston  was  helped  with 

all  the  appliances  of  hat,  papier  mache,  grease,  blacklead  powder, 
a  bottle  of  oil  to  drain  through  the  hat  and  lubricate  the  sides,  and 
an  iron  weight  above  all  to  prevent  the  piston  leaving  the  paper 
behind  in  its  stroke— after  some  imperfections  of  the  valves  were 
remedied,  the  engine  makes  500  strokes  with  about  two  hundred 
weight  of  coals."  In  another  month  or  two,  with  better  conden- 
sation, it  "makes  2,000  strokes  with  one  hundred  weight  of  coals." 
Emery,  carborundum  and  alundum  wheels  are  developed  from 
the  grindstone  of  the  distant  past.  That  stone  gives  a  straight- 
line  finish  or  edge  to  the  surfaces  submitted  to 
it;  and  as  the  work  is  shifted  in  front  of  the  Emery  and 

.  .  .  Carborundum 

stone  these  surfaces  may  take  a  curved  or  other  wheels 

contour.    But  a  grindstone,  let  it  be  as  hard  as 
can  be  found,  is  not  hard  enough  to  take  and  keep  any  other  than 
a  cylindrical  form.     Its  successors  of  to-day,  the  carborundum 
wheel  especially,  can  be  of  varied  shapes,  and  transfer  these  to 
metal  with  celerity  and  economy. 

Carborundum,  a  compound  of  silicon  and  carbon,  is  produced 
at  Niagara  Falls,  New  York,  by  a  process  devised  by  Mr.  E.  G. 
Acheson.  In  an  electrical  furnace  are  placed  granulated  coke, 
sand,  a  little  salt,  and  some  sawdust  to  keep  the  mixture  porous 
and  allow  generated  gases  to  escape  freely.  The  crystals  of 
carborundum  thus  produced  require  seven  horse-power  hours 
for  each  pound;  in  hardness  they  are  excelled  by  the  diamond 


102 


FORM— GRINDING 


Emery  wheels. 


only.  United  under  severe  hydraulic  pressure  by  a  vitrified 
bond  they  are  eight  times  as  efficient  as  emery  in  abrasion.  Car- 
borundum wheels  are  re- 
placing lathes  as  a  means 
of  finishing  axles,  piston- 
rods  and  rolls ;  their  accur- 
acy is  unsurpassed,  while 
they  demand  but  one  third 
the  time  needed  by  a  steel 
tool. 

At  the  very  dawn  of  art 
moist  clay  was  molded  into 
useful  plates  and  bowls. 
This  foreran  not  only  all 
that  the  potter  has  since 
accomplished,  but  all  that 


Carborundum  Co.,  Niagara  Falls,  N.  Y. 
Carborundum  wheel  edges. 


has   been   achieved   in   the 
foundry  and  the  mint.     In 


PRESSES  AND  STAMPS  103 

making  bricks,  tiles,  and  terra  cotta,  the  first  task  is  to  make  the 
clay  plastic,  then  advantage  is  taken  of  its  plasticity.  In  like 
manner  we  heat  a  metal  to  fluidity,  and  then  pour  it  into  a  mold 
to  make  a  fence  rail,  a  stove  plate,  or  a  car 

wheel.      An    electric    bath    refines    upon    this  Form  m 

~  .   .  ,.        .  Plastic  Arts. 

process.      Copper,   let   us   say,   dissolves   in   a 
tank,  and  concurrently  its  particles  are  deposited  on  a  mold  from 
which  the  metal  can  be  readily  stripped,  avoiding  the  distortion 
inevitable  when  heat  has  come  into  play. 

Within  the  past  ten  years  concrete  has  grown  into  much  import- 
ance as  a  building  material,  especially  as  reinforced  with  steel.  It 
is  a  great  deal  easier  and  cheaper  to  pour  a  wall  into  molds  than 
to  lay  courses  of  brick,  or  cut  and  dispose  stone-work.  Elsewhere 
in  this  book  a  few  pages  are  given  to  reinforced  concrete,  and  its 
applications. 

Pressing,  like  molding,  has  of  late  years  much  extended  its 
range  of  forms.  In  germ  it  goes  back  to  the  distant  day  when 
seals  were  impressed  upon  clay  tablets,  and 


coins  or  medals  were  struck   from  hard  ma-  30 


trices.  In  glass  manufacture  the  press  has  been 
used  for  centuries.  Cheap  pressed  tumblers  and  bowls  have  long 
been  accompanied  by  cheap  metal  pots  and  pans,  plates  and  basins, 
stamped  by  machinery.  To-day  much  enlarged  and  improved, 
such  machinery,  as  a  Bliss  press,  makes  a  kitchen  sink  from  a 
sheet  of  steel,  forms  gears  and  pinions  from  round  bars  of  metal, 
and  executes  the  intricate  curves  of  a  mandolin  in  a  plate  of 
aluminum.  For  a  good  while  the  spinning  lathe  gave  us  from  thin 
metallic  sheets  a  variety  of  cups,  saucers,  dishes,  parts  of  kettles, 
lamps,  and  the  like.  To-day  each  of  these  articles  is  produced  by 
a  single  blow  of  a  die,  proving  that  metals  are  plastic  in  a  degree 
unsuspected  in  former  days.  Thus  it  comes  about  that  the  seams 
necessary  to  the  tinman  and  the  coppersmith,  with  all  their  liability 
to  leaks  and  uncleanliness,  have  been  largely  dismissed  and  may 
soon  be  wholly  banished.  Pressing  is  illustrated  on  pages  184  to 
1  86  of  this  book. 

To-day  we  are  rich  in  old  and  new  facilities  for  the  bestowal 
of  form.    To  confer  shape  by  division  we  have  an  immense  variety 


104    FORM— VARIOUSLY  CONFERRED 


Means  of  Con- 
ferring Form. 


of  knives,  scissors,  saws,  axes,  hatchets  and  shears.  These,  to- 
gether with  hammers,  chisels  and  gouges  enable  us  to  disengage 
from  a  mass  not  merely  a  simple  rail,  panel,  or 
Old  and  New  table-top,  but  a  carving  or  a  statue.  Surfaces 
are  smoothed  with  a  rasp,  a  file,  a  plane;  sand 
is  rubbed  on  abrasively,  or  falls  from  a  height, 
or  is  forcibly  blown  with  a  blast  of  steam  or  air.  Emery  either 
spread  on  paper,  or  glued  upon  a  wheel,  grinds  with  an  accuracy 
and  speed  new  to  art ;  and  all  that  emery  can  do  is  outdone  by  car- 
borundum and  alundum,  which  slice  away  metal  as  if  chalk,  be  its 
hardness  what  it  may.  Perforation  is  accomplished  with  rotary 

drills,  or  by  a  sandblast,  or 
on  occasion  by  corrosive 
acids— a  final  resource  in 
treating  refractory  stone. 
Rolls  of  tremendous  power 
reduce  iron  and  steel  in 
thickness,  and,  when  suitably 
shaped,  confer  form  on  rail- 
road rails,  girders  and  the 


Diagram  of  rolls  to  reduce  steel  in 
thickness. 


like.  Every  tool  and  imple- 
ment, old  or  new,  is  now  em- 
bodied in  machines  of  gigan- 
tic force,  or  multiple  effect,  so  that  the  skill  of  an  earlier  genera- 
tion is  either  not  in  demand  at  all  or  passes  to  tasks  of  a  delicacy 
never  attempted  before.  It  is  by  virtue  of  presses,  enormous  in 
power,  that  to-day  shapes  are  bestowed  on  metals  in  successful 
rivalry  with  the  ancient  art  of  the  founder  himself.  Indeed  the 
art  of  conferring  form  by  pouring  a  liquid  into  molds  is  at  this 
hour  largely  exercised  in  work  where  heat  plays  no  part  what- 
ever,—as  in  the  tasks  of  the  builder  in  concrete,  the  labors  of  the 
electrician  as  he  employs  a  bath  to  separate  a  metal  from  its  ore, 
or  to  plate  a  surface  with  silver  or  gold. 

In  strong  contrast  with  the  varied  resources 
of  modern  toil  are  the  simple  tools  and  imple- 
ments of  prehistoric  skill  which,  modified  much 
or  little,  are  at  this  hour  still  indispensable  to  the  mechanic,  the 
builder,  the  engineer..  These  simple  aids  early  became  ad- 


Use  Creates 
Beauty. 


BEAUTY  THROUGH  USE  105 

mirable  in  form  so  as  to  be  all  the  more  useful.    Says  Mr.  George 
Bourne : — 

"The  beauty  of  tools  is  not  accidental  but  inherent  and  essential. 
The  contours  of  a  ship's  sail  bellying  in  the  wind  are  not  more  in- 
evitable, nor  more  graceful,  than  the  curves  of  an  adze-head  or  of 
a  plowshare.  Cast  in  iron  or  steel,  the  gracefulness  of  a  plow- 
share is  less  destructible  than  the  metal,  yet  pliant,  within  the 
limits  of  its  type.  It  changes  for  different  soils ;  it  is  widened  out 
or  narrowed ;  it  is  deep-grooved  or  shallow ;  not  because  of  caprice 
at  the  foundry  or  to  satisfy  an  artistic  fad,  but  to  meet  the  tech- 
nical demands  of  the  expert  plowman.  The  most  familiar  ex- 
ample of  beauty  indicating  subtle  technique  is  supplied  by  the  ad- 
mired shape  of  boats,  which  is  so  variable,  says  an  old  coast- 
guardsman,  that  the  boat  best  adapted  for  one  stretch  of  shore 
may  be  dangerous  if  not  entirely  useless  at  another  stretch  ten 
miles  away.  And  as  technique  determines  the  design  of  a  boat, 
or  of  a  wagon,  or  of  a  plowshare,  so  it  controls  absolutely  the 
fashioning  of  tools,  and  is  responsible  for  any  beauty  or  form  they 
possess.  Of  all  tools,  none,  of  course,  is  more  exquisite  than  a 
fiddle-bow.  But  the  fiddle-bow  never  could  have  been  perfected, 
because  there  would  have  been  no  call  for  its  tapering  delicacy,  its 
calculated  balance  of  lightness  and  strength,  had  not  the  violinist's 
technique  reached  such  marvelous  fineness  of  power.  For  it 
is  the  accomplished  artist  who  is  fastidious  as  to  his  tools;  the 
bungling  beginner  can  bungle  with  anything.  The  fiddle- 
bow,  however,  affords  only  one  example  of  a  rule  which  is 
equally  well  exemplified  by  many  humbler  tools.  Quarry- 
man's  pick,  coachman's  whip,  cricket-bat,  fishing-rod,  trowel, 
all  have  their  intimate  relation  to  the  skill  of  those  who  use  them ; 
and  like  animals  and  plants  adapting  themselves  each  to  its 
own  place  in  the  universal  order,  they  attain  to  beauty  by  force 
of  being  fit.  That  law  of  adaptation  which  shapes  the  wings 
of  a  swallow  and  prescribes  the  poise  and  elegance  of  the 
branches  of  trees,  is  the  same  that  demands  symmetry  in  the 
corn-rick  and  convexity  in  the  barrel ;  and  that,  exerting  itself 
with  matchless  precision  through  the  trained  senses  of  hay- 
makers and  woodmen,  gives  the  final  curve  to  the  handles  of 
their  scythes  and  the  shafts  of  their  axes.  Hence  the  beauty  of 


106  FORM— CONVENIENCE 

a  tool  is  an  unfailing  sign  that  in  the  proper  handling  of  it  tech- 
nique is  present." 1 

In  the  course  of  a  judicious  review  of  the  mechanical  engineer- 
ing of  machine  tools,  Mr.  Charles  Griffin  has  this  to  say  regarding 
convenience :— 2 

"A  tool  is  an  investment,  the  interest  which  it  earns  depending 
on  the  amount  of  work  it  turns  out  in  a  given  time.    This  depends 
largely  on  its  convenience  of  manipulation,  in- 
convenience       volving   a    study    of    levers,    handles,    wheels, 
in  the  Use  of        knobs  and  other  auxiliary  devices,  their  shape 
and  place  with  reference  to  the  best  adaptation 
to  the  average  human  frame,  the  ease  and  extent  of  their  motions, 
and  the  rapidity  with  which  these  motions  may  be  accomplished. 
The  position  of  the  operator,  his  natural  tendencies,  the  motions 
he  will  go  through,  all  have  to  be  imagined  in  view  of  the  attain- 
ment of  his  maximum  convenience.     This  study,  in  the  absence 
of  any  counterpart  of  the  proposed  machine,  often  forces  a  resort 
to  rough  models,  or  in  lieu  of  this,  a  full-size  blackboard  sketch, 
extending  to  the  floor,  upon  which  the  location  of  parts  may  be 
tried  for  convenience." 

In  the  National  Museum,  at  Washington,  the  visitor  as  he  in- 
spects examples  of  American  aboriginal  art  is  astonished  at  its 
Resources  Rich      union  °f  utility  and  beauty.    Boat  and  paddle, 
or  Meagre  as        spear  and  hook,  basket  and  vase,  are  as  ad- 
Affecting  mirable  in  form  as  useful  in  traveling,  fishing, 
Invention.  or  carrying  corn  or  water.     How  far  an  ab- 
original designer  may  go  largely  turns  upon  what  variety  of  re- 
sources Nature  offers  him.    No  few  score  families  on  a  lonely  islet 
of  the  Pacific  can  possibly  rival  the  cloths  and  carvings  displayed 
by  tribes  ranging  a  Pennsylvania,  or  a  California,  abounding  with 
diverse  minerals,  plants  and  animals.     When  skill  and  invention 
occupy  so  rich  a  land  they  flower  into  the  highest  creations  of  ab- 
original art.    And  yet  it  may  be  that  the  very  fewness  of  a  de- 
signer's resources  but  spurs  him  to  all  the  more  ingenuity.     It 
depends  upon  who  the  man  is.    As  we  look  upon  a  collection  of 
Eskimo  harpoons  and  knives,  coats  and  kayaks,  we  marvel  that 

1  Cornhill  Magazine,  London,  September,  1903. 
a  Engineering  Magazine,  New  York, -May,  1901, 


ABORIGINAL  ART  107 

all  these  should  be  produced  with  so  much  excellence  and  variety 
from  a  scanty  store  of  bones  and  teeth,  sinews  and  hides,  with  but 
little  iron  or  none  at  all.1 

*Two  unrivalled  books  on  aboriginal  invention  have  been  written  by 
Mr.  Otis  T.  Mason,  Curator  of  the  Department  of  Ethnology  at  the 
National  Museum,  Washington: — "Woman's  Share  in  Primitive  Culture," 
New  York,  D.  Appleton  &  Co.,  1894;  and  "The  Origin  of  Inventions," 
London,  Walter  Scott  Publishing  Co.,  and  New  York,  C.  Scribner's  Sons, 
1905.  Both  volumes  are  fully  illustrated. 

The  annual  reports  of  the  Bureau  of  Ethnology,  Smithsonian  Institution, 
Washington,  describe  and  illustrate  American  aboriginal  art  so  fully  and 
admirably  as  to  be  indispensable  to  the  student 


CHAPTER  IX 


Aboriginal 
Art. 


FORM— Continued.    FORM  IN  ABORIGINAL  ART,  AS  AFFECTED 

BY  MATERIALS:  OLD  FORMS  PERSIST  IN 
NEW  MATERIALS 

Nature^  gifts  first  used  as  given,  then  modified  and  copied  .  .  .  Rigid 
materials  mean  stiff  patterns  .  .  .  New  materials  have  not  yet  had  their 
full  effect  on  modern  design. 

SO  multiplied  are  the  resources  of  modern  industry  that  de- 
sired forms  are  created  at  will,  almost  without  regard  to  the 
material  employed.  It  is  not  so  in  primitive  art,  to  which  for  a 
brief  space  we  will  now  turn  so  that  our  survey  of  form,  though 
all  too  cursory,  may  be  refreshed  by  a  contrast 
of  old  with  new.  Let  us  begin  with  a  glance  at 
some  of  the  aids  with  which  man  first  provided 
himself,  taking  the  gifts  of  nature  just  as  they  were  offered.  In 
large  areas  of  the  Southern  States,  and  of  Central  America,  the 

gourd  for  ages  has  been  a 
common  plant,  and  has  long 
served  many  Indian  tribes  as 
a  water  pitcher.  On  sea- 
shores, where  the  gourd  did 
not  grow,  conch-shells  were- 
used  instead,  their  users 
breaking  away  the  outer 
spines  and  the  inner  whorls, 
leaving  within  a  space  clean 
and  clear.  Both  gourds  and 
shells  gave  their  forms  to 
the  clay  vessels  which  suc- 
ceeded them. 

In  Zuni  land,  says  Mr.  F. 
H.  Gushing,  the  first  vessels 
for  water  were  sections  of 


Gourd-shaped  vessel  from  Arkansas. 

"Pottery  of  the  Ancient  Pueblos." 

W.  H.  Holmes. 

108 


cane  or  tubes  of  wood.    We 
may  infer  that  the  wooden 


ABORIGINAL  ART 


109 


tubes  were  copied  from  the  cane  stems.    What  at  first  was  pas- 
sively accepted  as  nature  gave  it,  was  afterward  changed  a  little, 


Gourd  and  derived  forms.     "Pottery  of  the  Ancient  Pueblos." 
W.  H.  Holmes. 


and  then  was  step  by  step  changed  much,  so  that  at  length  there 
grew  up  processes  of  manufacture.  There  was,  for  example,  in 
California  a  wealth  of  osiers,  reeds,  and  roots  well  suited  for  mak- 
ing baskets ;  these  at  last  were  perfected  as  water-tight  receptacles 
neither  brittle  like  a  shell  nor  liable  to  a  gourd's  swift  decay.  Be- 
ginning probably  in  mere  wattling,  in  the  rude  plaiting  of  mats 
and  roofs,  the  weaver  came  gradually  upon  finer  and  stronger 
materials  than  at  first,  with  equal  pace  rising  to  new  delicacy  of 
finish  and  beauty  of  design.  At  the  National  Museum  in  Wash- 


Pomo  basket.    National  Museum,  Washington. 


ington,  the  Hudson  collection  of  Indian  baskets  from  California 
includes  the  finest  specimen  in  the  world,  a  Pomo  basket.  Its 
sixty  stitches  to  the  running  inch  were  possible  only  through 


110  FORM— BASKETRY 

using  the  carex  root,  easily  divided  into  threads  at  once  slender 
and  strong.1 

It  is  interesting  to  observe  the  limitation  imposed  upon  a 
primitive  designer  by  the  qualities  of  the  leaf,  shell,  or  cane  in  his 
hands,  the  way  in  which  these  qualities  point  him  to  the  forms  in 
which  he  may  excel.  Of  this  we  have  capital  examples  in  the 
basket-work  of  the  North  American  aborigines  as  described  by 
Mr.  Otis  T.  Mason,  in  the  report  of  the  Smithsonian  Institution, 
1883-84.  He  says :  "Along  the  coast  of  British  Columbia  the 


Bilhoola  basket  of  wo^ren  cedar  bast.     "B^s^et  work  of  North 
American  Aborigines."    Otis  T.  Mason. 


great  cedar  (Thuja  gigantea)  grows  in  the  greatest  abundance, 
and  its  bast  furnishes  a  textile  material  of  the  greatest  value. 
Here  in  the  use  of  this  pliable  material  the  savages  seem  for  the 
first  time  to  have  thought  of  checker-weaving.  Mats,  wallets, 
and  rectangular  baskets  are  produced  by  the  plainest  crossing  of 
alternate  strands  varying  in  width  from  a  millimeter  to  an  inch. 
Ornamentation  is  effected  both  by  introducing  different-colored 
strands  and  by  varying  the  width  of  the  warp  or  the  woof  threads. 
.  .  .  It  is  not  astonishing  that  a  material  so  easily  worked 
should  have  found  its  way  so  extensively  in  the  industries  of  this 

1  Many  of  the  handsomest  baskets  at  the  National  Museum,  as  well  as 
baskets  from  other  great  collections,  are  illustrated,  partly  in  color,  in 
"Indian  Basketry,"  by  Otis  T.  Mason,  curator  of  the  ethnological  depart- 
ment of  the  National  Museum.  The  publishers  are  Doubleday,  Page  & 
Co.,  New  York. 


MATERIALS  AFFECT  DESIGN        111 


stock  of  Indians.     Neither  should  we  wonder  that  the  checker 
pattern  in  weaving  should  first  appear  on  the  west  coast  among 
the    only    peoples    possessing    a    material 
adapted  to  this  form  of  ornamentation." 

Referring  to  the  water-bottles  of  the  Pai 
Utes,  Mr.  Mason  says :  "This  style  can  be 
made  coarse  or  fine,  according  .  to  the 
material  and  size  of  the  coil  and  outer 
threads.  If  two  twigs  of  uniform  thickness 
are  carried  around,  the  stitch  will  be  hatchy 
and  open ;  but  if  one  of  the  twigs  is  larger 
than  the  other,  or  if  yucca  or  other  fibre 
replace  one  of  them  and  narrower  sewing 

material  be  used,  the  texture  will  be  much  finer."  Baskets  and 
rain-hats,  as  woven  by  Haidas  and  many  other  tribes,  are  water- 
proof when  wet,  owing  to  the  closeness  of  their  texture. 

When  reeds  or  somewhat  rigid  fibres  are  woven,  they  compel 
a  straightness  of  edge  in  patterns  and  designs.  A  wave  has  to  be 
suggested  by  stepped  or  broken  lines,  and  so 
we  have  a  rectilinear  meander  or  fret,  in  con- 
trast with  its  free-hand  form  as  developed  in 
a  woven  fabric.  Under  the  constraint  of  her  material  a  squaw 
as  she  weaves  a  design  into  a  basket,  must  give  squareness  to  a 


A  square  inch  of  the 
Bilhoola  basket. 


Idiom  of 
Material. 


A  free-hand  scroll.  The  same  developed  in  a 

woven  fabric. 
"Form  and  Ornament  in  Ceramic  Art."    W.  H.  Holmes. 


contour  which  would  be  somewhat  rounded  were  it  executed  in 
delicate  threads.  This  is  clear  in  the  human  figures  of  the  Pomo 
basket  shown  on  page  109 ;  and  in  those  of  a  Yokut  basket  bowl, 
also  in  the  National  Museum  in  Washington,  illustrated  on  the 
next  page. 


112  FORM-BASKETRY 

Stone  and  brick-work,  in  their  rectilinear  shapes,  impose  a  rigid- 
ity in  architectural  design  from  which  modern  bricks,  in  their  rich 
variety  of  flat  and  curved  surfaces,  have  wrought  emancipation. 


Yokut  basket  bowl. 
"Basket  Work  of  North  American  Aborigines."     Otis  T.  Mason. 

In  the  new  residential  streets  of  St.  Louis,  for  example,  the  archi- 
tecture owes  much  of  its  freedom  and  beauty  to  the  new  shapes 
in  which  brick  is  now  manufactured.  Even  wider  liberty  than 
now  falls  to  the  lot  of  the  brick-maker  has  always  been  enjoyed 
by  the  potter.  In  his  hands  clay  lends  itself  to  any  desired  imita- 
tion, to  any  fresh  design  however  fanciful ;  what  is  more  it  in- 
vites those  modifications  of  old  forms  in  which  art  takes  its  chief 
forward  strides.  All  but  infinite  are  the  variations  which  Jap- 


JAPANESE  ART  113 

anese  potters  have  played  on  the  shapes  of  vases,  jars,  kettles, 
and  basins,  each  clearly  true  to  its  type,  while  at  the  same  time 
original  in  a  pleasing  way.  How  the  Japanese  artist  in  clay  has 
rejoiced  in  his  freedom  is  exemplified  in  the  collection  of  Jap- 
anese pottery  at  the  Museum  of  Fine  Arts,  in  Boston.  Says  Mr. 
Edward  S.  Morse,  who  brought  this  collection  together :  "Uten- 
sils for  every  day  life,  terra  cotta  funeral  urns,  large  terra  cotta 
bowls,  weights  for  fishing  nets,  brush  handles,  and  even  clothes- 
hooks  are  in  Japan  made  of  pottery.  Where  we  use  silver  and 
other  metals,  or  glass,  in  making  articles  for  daily  use,  the  Jap- 
anese use  pottery."  He  adds :  'The  prehistoric  pottery  of  Japan 
was  modeled  by  hand,  and  to-day  in  various  parts  of  the  empire, 
this  ancient  art  is  continued  in  its  prehistoric  form.  There  are 
many  potters  in  Japan  who  are  still  at  work  using  only  the  hand 
in  making  bowls,  delicate  tea-pots,  and  dishes  of  various  kinds. 
The  pottery  vessels  offered  at  Shinto  shrines  are  usually  made 
without  the  use  of  the  wheel  and  are  unglazed.  The  potter's 
wheel  was  brought  to  Japan  from  Korea.  The  first  was  probably 
the  kick-wheel  used  in  Satsuma  and  other  southern  provinces." 
The  Japanese  employ  not  only  clay  but  wood  in  methods  that 
richly  repay  study.  Says  Mr.  Ralph  Adams  Cram : — "In  one 
respect  Japanese  architecture  is  unique :  it  is  a  style  developed 
from  the  exigencies  of  wooden  construction,  and  here  it  stands 
alone  as  the  most  perfect  mode  in  wood  the  world  has  known. 
As  such  it  must  be  judged,  and  not  from  the  narrow  canons  of 
the  West  that  presuppose  masonry  as  the  only  building  material. 
.  .  .  Perhaps  the  greatest  lesson  one  learns  in  Japan  is  that  of 
the  beauty  of  natural  wood,  and  the  right  method  of  treating  it. 
The  universal  custom  of  the  West  has  been  to  look  on  wood  as  a 
convenient  medium  for  the  obtaining  of  ornamental  form  through 
carving  and  joinery,  the  quality  of  the  material  itself  being  sel- 
dom considered.  In  Japan  the  reverse  is  the  case.  In  domestic 
work  a  Japanese  builder  shrinks  from  anything  that  would  draw 
attention  from  the  beauty  of  his  varied  woods.  He  treats  them 
as  we  do  precious  marbles,  and  one  is  forced  to  confess  that  under 
his  hand  wood  is  found  to  be  quite  as  wonderful  a  material  as 
our  expensive  and  hardly  worked  marbles.  In  Japan  one  comes 


114    FORM— DECIDED  BY  MATERIALS 

to  the  final  conclusion  that  stains,  paints,  and  varnish,  so  far  as 
interior  work  is.  concerned,  are  nothing  short  of  artistic  crimes."1 

In  strong  contrast  with  the  art  of  Japan  is  that  of  Egypt;  on 
the  banks  of  the  Nile  the  first  buildings  were  of  limestone,  suc- 
ceeded by  huge  structures  reared  from  Syene  granite,  with  no 
little  loss  in  delicacy  of  ornamentation.  It  was  only  when  marble, 
all  but  plastic  under  the  chisel,  was  adopted  by  the  Greek  sculptor, 
that  the  frieze  of  the  Parthenon  could  spring  into  life. 

Here  William  Morris  should  be  heard.  In  "Hopes  and  Fears 
for  Art,"  he  says :  "All  material  offers  certain  difficulties  to  be 
overcome  and  certain  facilities  to  be  made  the  most  of.  Up  to  a 
certain  point  you  must  be  master  of  your  material,  but  you  must 
never  be  so  much  the  master  as  to  turn  it  surly,  so  to  say.  You 
must  not  make  it  your  slave,  or  presently  you  will  be  its  slave 
also.  You  must  master  it  so  far  as  to  make  it  express  a  meaning, 
and  to  serve  your  aim  at  beauty.  You  may  go  beyond  that  neces- 
sary point  for  your  own  pleasure  and  amusement,  and  still  be  in 
the  right  way ;  but  if  you  go  on  after  that  merely  to  make  people 
stare  at  your  dexterity  in  dealing  with  a  difficult  thing,  you  have 
forgotten  art  along  with  the  rights  of  your  material,  and  you  will 
make  not  a  work  of  art,  but  a  mere  toy;  you  are  no  longer  an 
artist,  but  a  juggler.  The  history  of  art  gives  us  abundant  ex- 
amples and  warning  in  this  matter.  First  clear,  steady  principle, 
then  playing  with  the  danger,  and  lastly  falling  into  the  snare, 
mark  with  the  utmost  distinctness  the  times  of  the  health,  the 
decline,  and  the  last  sickness  of  art."  He  illustrates  this  in  detail 
from  the  history  of  mosaic  in  architecture. 

While  the  modern  artist  duly  respects  the  idiom  of  his  new 
materials,  their  diversity  and  refinement,  in  granting  him  the  ut- 
most freedom,  enable  him  to  attain  a  truth  of  execution  unknown 
before  to-day.  For  writing  on  papyrus  a  brush  had  to  be  used ; 
on  vellum  or  paper,  a  pen  or  pencil  may  also  be  employed,  tracing 
lines  no  wider  than  a  hair.  Our  grandmothers  were  fond  of  sew- 
ing on  a  perforated  card  a  motto  or  a  flower  in  silk  thread ;  such 
a  sampler  always  had  an  unpleasant  straightness  in  its  outlines. 


1  "Impressions  of  Japanese  Architecture  and  the  Allied  Arts,"  by  Ralph 
Adams  Cram.    New  York,  Baker  &  Taylor  Co.,  1905. 


INFLUENCE  OF  NEW  MATERIALS  115 


Sampler  on  cardboard,  exe- 
cuted in  silk  thread. 


When  in  weaving  silk  or  linen  there  may  be  two  hundred  threads 

to  the  running  inch  instead  of  ten,  the  designer  can  introduce 

curves  almost  as  flowing  as  if  he 

were  a  painter.     So  too  in  archi- 
tecture :  the  log  hut  was  perforce 

straight  in  its  every  line ;  stone  and 

brick  made  possible  the  arch;  iron 

and   steel   are   bringing   in   a   free 

choice   of   the   best   lines,   whether 

straight  or  curved,  all  with  a  new 

sprightliness,  as  witness  the  best  of 

our  office-buildings  in  New  York, 

such  as  the  Whitehall,  Trinity,  and 

Empire  Buildings. 
Art  in  its  early  stages  seldom  displays  any  outright  invention; 

with  all  the  force  of  habit  the  savage  artist  clings  to  old  familiar 

shapes,  and   it  is   interesting  to   remark   how 

dealing  with  a  new  material  may  lead  or  even          Old  Forms 

oblige  him  to  modify  a  traditional  form.    The      New  Materials 

Algonquins  inhabit  a  country  in  which  the  birch 

is  common.    They  cut  and  fold  its  bark  into  vessels  which,  when 

imitated  in  pottery,  have  an  unusual  rectangularity.     In  many 

Indian  tribes  it  was  custom- 
ary to  use  as  a  water-holder 
the  paunch  of  a  deer  or  a 
buffalo;  many  ancient  urns 
of  Central  America  have  an 


Bark  vessel,  and  derived  form  in  clay. 

"Form  and  Ornament  in  Ceramic 

Art"    W.  H.  Holmes. 


aperture  at  an  upper  ex- 
tremity, copied  from  the 
paunch,  in  every  case  with  a 

simplification  of  outline.  Winged  troughs  of  wood  were  un- 
doubtedly in  the  mind  of  the  man  who  made  the  earthen  vessel 
illustrated  on  the  next  page,  found  in  an  ancient  grave  in  Arkansas. 
As  usual  the  borrower  put  something  of  himself  into  his  work, 
reminding  us  that  the  law  of  evolution  is  descent  with  modifica- 
tion. An  earthen  vessel,  illustrated  on  the  next  page,  was 
plainly  copied  from  a  shell  vessel  such  as  the  specimen  found  not 
far  off,  in  Indiana.  When  the  Clallam  Indians,  of  the  State  of 


116         FORM— IN  ABORIGINAL  ART 


Washington,  began  to  weave  baskets,  they  imitated  the  forms  of 
their  rude  wicker  fish-traps.    The  like  persistence  was  shown  by 

the  Haida  squaws  when 
taught  by  the  missionaries  to 
make  mats  from  rags;  they 
repeated  their  ancient  twined 
model,  long  employed  for 
mats  and  hats  of  vegetable 
fibres.  As  in  America,  so 
also  in  Europe;  when  the 
makers  of  celts  passed  from 
stone  to  copper  or  bronze, 
they  reproduced  the  old 
forms,  and  only  gradually 
learned  to  economize  metal, 
so  much  stronger  than  stone, 
rmd  so  much  harder  to  get, 
by  narrowing  and  flattening  their  new  weapons  and  tools. 

Modern  manufacture  in  its  designs  gives  us  a  kindred  per- 
sistence of  old  forms  in  new 
things.  For  electric  illumi- 
nation we  have  bulbs  which 


Vase  from  tumulus.  St.  George,  Utah. 

'Tottery  of  the  Ancient  Pueblos." 

W.  H.  Holmes. 


Wooden  tray.     Clay  derivative. 

"Form  and  Ornament  in  Ceramic 

Art."     W.  H.  Holmes. 


recall  the  shape  of  a  candle- 
blaze,  or  surmount  an  old- 
fashioned  candlestick ;  a  gas- 
burner,  popular  for  fifty  years,  repeats  in  milky  porcelain  the 
whole  length  of  a  candle.  Gas-grates,  in  uncounted  thousands 


Shell   vessel    made    from   a 

Busycon  perversum,  found 

at  Ritchersville, 

Indiana. 


Earthen  vessel,  imitation  of 
shell,    Missouri. 


From  W.  H.  Holmes'  "Art  in  Shell  of  the  Ancient  Americans." 


OLD  FORMS  IN  MODERN  USES      117 

throughout  our  cities  every  winter,  offer  us  flames  which  flicker 
and  leap  over  asbestos  and  clay  molded  into  the  semblance  of  maple 
or  charcoal.  Nor  is  the  engineer  himself,  for  all  his  sternness  of 


Electric  lamps  in  candle  shapes. 

discipline,  quite  free  from  prolonging  the  reign  of  the  past,  even  at 
unwarrantable  cost.  When  steel  was  first  used  for  steam  boilers 
there  was  a  period  of  hesitation  during  which  the  metal  was  used" 
unduly  thick,  as  if  to  maintain  the  long  familiar  massiveness  of 
iron  structures.  When  automobiles  were  invented,  they  at  first 
closely  resembled  common  carriages.  To-day,  designers  have  de- 
parted from  tradition,  and  provide  us  with  horseless  vehicles  which 
respond  to  their  new  needs  in  ways  wholly  untrammeled  by  in- 
herited ideas.  In  an  automobile,  driven  by  steam  or  gasoline, 
there  must  be  due  disposition  of  fuel,  of  machinery,  of  cooling 
apparatus,  all  -so  combined  as  to  bring  the  center  of  gravity  as 
low  as  may  be  best,  affording  ready  access  to  any  part  needing 
lubrication,  repair,  or  renewal;  throughout  there  must  be  the 
minimum  of  dead  weight,  of  friction,  and  of  liability  to  derange- 
ment; all  with  means  of  easy,  quick,  and  certain  control.  Why 


118 


FORM— INHERITED 


should  these  requirements  be  deferred  to  repeating  the  model  of 
a  carriage  drawn  by  a  horse?  In  Europe,  to  this  hour,  the  rail- 
road carriages  are  an  imitation  of  the  old  road-coaches,  horse 
carriages  slightly  modified.  America,  fortunately,  from  the  first 


Notre  Dame  de  Bonsecours,  Montreal.    Before  restoration. 

has  had  cars  directly  adapted  to  railroad  exigencies,  with  a  thor- 
oughfare extending  the  whole  length  of  a  train,  avoiding  the 
box-like  compartments  which  may  give  the  lunatic  or  the  mur- 
derer an  opportunity  to  work  his  will. 

Sometimes  an  inherited  form  taken  to  a  new  home  proves  to 
be  faulty  there,  and  is  discarded.  When  Normandy  sent  forth 
its  children  to  Canada,  they  built  on  the  shores  of  the  St.  Law- 
rence just  such  high-pitched  roofs  as  had  sheltered  them  in  Caen 
and  Rouen.  An  example  remains  at  Montreal  in  the  roof  of 


w  : 

M 

W    = 


ARCHITECTURAL  DESIGN  119 

Notre  Dame  de  Bonsecours.  But  in  Montreal  and  Quebec  the 
snowfall  is  much  heavier  than  in  Northern  France,  and  the  Nor- 
man roofs  at  intervals  from  December  to  March  were  wont  to  let 
loose  their  avalanches  with  an  effect  at  times  deadly.  To-day, 
therefore,  in  French  Canada  many  of  the  roofs,  especially  in 
towns  and  cities,  are  flat  or  nearly  flat,  while  the  best  models 
quite  reverse  the  old  design.  In  breadths  somewhat  concave  they 
catch  the  snow  as  in  a  basin,  and  allow  it  to  melt  slowly  so  as  to 
run  down  a  pipe  through  the  center  of  the  building. 

Under  our  eyes,  day  by  day,  iron  and  steel  are  taking  the  place 
of  stone  and  wood  in  architecture  and  engineering ;  yet  the  force 
of  habit  leads  us  to  continue  in  metal  many  troublesome  details 
which  were  imperative  in  the  weak  building  materials  of  genera- 
tions past.  It  was  as  recently  as  the  autumn  of  1903  that  the  first 
large  American  theater  was  opened  having  no  columns  to  obstruct 
views  of  its  stage.  The  architects  of  the  New  Amsterdam 
Theater,  New  York,  simply  by  availing  themselves  of  the  strength 
of  steel  cantilevers  have  shown  that  henceforth  all  large  audi- 
toriums may  be  free  from  obstructions  to  a  view  of  the  stage, 
pulpit  or  platform.  See  facing  page  118. 

Modern  architecture,  in  the  judgment  of  an  eminent  critic,  has 
lot  yet  fully  responded  to  its  new  materials  and  methods.  Says 
VTr.  Russell  Sturgis,  of  New  York,  in  "How  to  Judge  Archi- 
tecture":— "Every  important  change  in  building,  in  the  past,  has 
been  accomplished  by  a  change  in  the  method  of  design,  so  that 
even  in  the  times  of  avowed  revival  there  was  seen  no  attempt 
to  stick  to  the  old  way  of  designing  while  the  new  method  of 
construction  was  adopted;  now  in  the  nineteenth  century,  and  in 
what  we  have  seen  of  the  twentieth  century,  our  great  new  sys- 
tems of  building  have  flourished  and  developed  themselves  with- 
out effect  as  yet  upon  our  methods  of  design.  We  still  put  a 
simulacrum  of  a  stone  wall  with  stone  window  casings  and  pedi- 
ments and  cornices  and  great  springing  arches  outside  of  thin, 
light,  scientifically  combined,  carefully  calculated  metal— the 
appearance  of  a  solid  tower  supported  by  a  reality  of  slender 
props  and  bars." 


CHAPTER  X 


SIZE 


Heavenly  bodies  large  and  small  .  .  .  The  earth  as  sculptured  a  little  at 
a  time  .  .  .  The  farmer  as  a  divider  .  .  .  Dust  and  its  dangers  .  .  . 
Models  may  mislead  .  .  .  Big  structures  economical  .  .  .  Smallness  of 
atoms  .  .  .  Advantages  thereof  ...  A  comet  may  be  more  repelled  by 
the  sun's  light  than  attracted  by  his  mass. 

BUILDINGS,  carriages,  structures  of  all  kinds,  whether 
reared  by  art  or  nature,  often  resemble  one  another  in  form 
while  varying  much  in  size.  Differences  of  dimensions  are  of 
importance  to  the  inventor  and  discoverer,  and  will  be  here  briefly 
considered,  beginning  with  a  few  of  their  obvious  and  elementary 
aspects. 

One  frosty  evening  I  sat  with  three  young  pupils  in  a  room 
warmed  by  a  grate-fire.  Shaking  out  some  small  live  coals,  I 
bade  the  boys  observe  which  of  them  turned 
black  soonest.  They  were  quick  to  see  that 
the  smallest  did,  but  they  were  unable  to  tell 
why,  until  I  broke  a  large  glowing  coal  into  a  score  of  fragments, 
which  almost  at  once  turned  black.  Then  one  of  them  cried, 

"Why,  smashing  that 
coal  gave  it  more  sur- 
face !"  This  young 
scholar  was  studying 
the  elements  of  as- 
tronomy that  year,  so 
I  had  him  give  us 
some  account  of  how 
the  planets  differ 
from  one  another  in 
size,  how  the  moon 
compares  with  the 
earth  in  volume,  and 
how  vastly  larger 


Cinders  Big 
and  Little. 


Cinders  large  and  small  on  hearth. 


A  CUBE  SUBDIVIDED 


121 


than  any  of  its  worlds  is  the  sun.  Explaining  to  him  the  fiery 
origin  of  the  solar  system,  I  shall  not  soon  forget  his  delight- 
in  which  the  others  presently  shared — when  it  burst  upon  him 


First  Cut 


Second  Cut 
Third  Cut 


Additional  Surfaces- 
obtained  by  — 


A  cube  as  subdivided  into  8  cubes  of  4  times 
more  surface. 

that  because  the  moon  is  much  smaller  than  the  earth  it  must  be 
much  cooler;  that  indeed,  it  is  like  a  small  cinder  compared  with 
a  large  one.  It  was  easy  to  advance  from  this  to  understanding 
why  Jupiter,  with  eleven  times  the  diameter  of  the  earth,  still 
glows  faintly  in  the  sky  by  its  own  light,  and  then  to  comprehend- 
ing that  the  sun  pours  out  its  wealth  of  heat  and  light  because  the 


122 


SIZE 


immensity  of  its  bulk  means  a  comparatively  small  surface  to 
radiate  from. 

To  make  the  law  concerned  in  these  examples  definite  and  clear, 
I  took  eight  blocks,  each  an  inch  cube,  and  had  the  boys  tell  me 
how  much  surface  each  had— six  square  inches.     Building  the 
eight  blocks  into  one  cube,  they  then  counted  the  square  inches 
of  its  surface — twenty- four :  four  times  as  many  as  those  of  each 
separate  cube.     With  twenty-seven  blocks  built  into  a  cube,  that 
structure  was  found  to  have  a  surface  of  fifty-four  square  inches 
— nine  times  that  of  each  component  block.    As  the  blocks  under- 
went the  building  process,  a  portion  of 
their  surfaces  came  into  contact,  and 
thus  hidden  could  not  count  in  the  outer 
surfaces  of  the  large  cubes.    The  outer 
surfaces  of  'these  large  cubes  I  then 
painted  white;  when  each  was  separ- 
ated   into   its    eight   or   twenty-seven 
blocks,  we  saw  in  unpainted  wood  how 
surfaces     were     increased     by     this 
separation     into    the    original     small 
cubes.      Observation   and   comparison 
brought  the  boys  to  the  rule  involved 
in   these   simple   experiments.     They 
wrote :  Solids  of  the  same  form  vary 

in  surface  as  the  square,  and  in  contents  as  the  cube,  of  their  like 
dimensions. 

This  elementary  law  I  traced  that  year  in  a  variety  of  illustra- 
tions presented  in  "A  Class  in  Geometry,"  published  by  A.  S. 
Barnes  &  Co.,  New  York.  Our  excursions,  since  extended,  are 
here  given  as  an  example  of  the  knitting  value  of  a  pervasive  rule 
kept  constantly  in  mind. 

Our  planet  in  diverse  ways  illustrates  the  law,  just  stated,  of 
surfaces  and  volumes.  Forces  of  unresting  activity  quietly  trans- 
form the  hills  and  plains,  the  sea  coasts  and 
Earth  Sculpture,     lake  shores  of  the  world,  and  so  gradually  that 
in  many  cases  detection  proceeds  only  by  noting 
the  changes  wrought  in  a  century.    For  the  most  part  these  forces 


Cube  built  of  27  cubes  of  9 
times  more  surface. 


GAIN  IN  MINUTENESS  123 

break  up  large  masses  into  fragments,  or  slowly  wear  away  the 
surfaces  of  rocks  into  dust.  A  lichen  takes  root  on  a  granite 
ledge,  and  in  a  few  years  reduces  the  rock  to  powder.  Rain  al- 
ways contains  a  little  acid,  so  that  in  time  flint  itself  is  consumed, 
for  all  its  hardness.  Water  soaking  through  soils  to  form  under- 
ground streams  has  hollowed  out  vast  caves,  as  notably  in  Vir- 
ginia and  Kentucky.  Limestones  and  sandstones  are  of  open 
texture,  and  take  up  much  moisture  into  their  pores;  in  cold 
weather  this  freezes,  and  in  expansion  wedges  off  thin  flakes  of 
stone.  In  the  North  one  sees  the  ground  strewn  with  such 
splinters  when  the  warm  April  sun  has  melted  the  snow  from  be- 
side a  limestone  fence.  Watch  the  rills  as  they  descend  a  hillside 
during  a  rainstorm  and  just  afterward.  They  are  dark  with  mud, 
and  on  steep  declivities  they  carry  down  pebbles  and  bits  of 
broken  stone,  building  up  valleys  at  the  expense  of  high  ground. 
Fed  on  a  huge  scale  by  such  mud,  the  Mississippi  River  bears  in 
suspension  to  the  Gulf  of  Mexico  a  little  more  than  a  pound  of 
solid  matter  in  every  cubic  yard,  a  prime  example  of  how  the 
waters  of  the  globe  gain  upon  the  land.  The  Falls  of  Niagara 
have  retreated  several  miles  from  their  original  plunge ;  the  carv- 
ing of  their  channel  has  been  wrought  much  less  by  the  rushing 
waters  than  by  their  burden  of  abrading  earth  and  sand.  The 
ceaseless  churning  of  water  at  the  foot  of  the  Falls  cuts  back 
into  the  rock,  undermining  its  upper  layers,  so  that  ever  and  anon 
they  break  off  from  the  brink  of  the  cataract,  with  the  effect  that 
the  stream  steadily  retires. 

Throughout  the  ocean  are  strong  currents  to  be  constantly  sur- 
veyed and  charted  on  the  mariner's  behalf.  These  currfets  trans- 
port fine  mud,  and  organisms  living  and  dead.  Corals  flourish 
best  where  such  currents  fetch  an  abundant  supply  of  food,  just 
as  plants  thrive  best  in  rich,  loose  soil.  Life  in  the  sea  just  like 
life  on  land  is  thtts  dependent  on  forces  which  divide  large  masses 
into  small,  and  distribute  these  small  masses  over  wide  areas| 
chiefly  by  water -carriage. 

Inventors  have  taken  a  hint  from  nature  as  she  carries  a  burden 
of  mud  and  pebbles  in  a  rapid  stream  of  water.  A  modern  method 
of  deepening  a  water  course  is  to  reduce  to  fine  silt  the  surface 


124  SIZE 

of  its  bed,  and  then  remove  this  silt  with  a  powerful  stream. 
Water  in  swift  eddies  both  lifts  and  bears  away  not  only  clay, 
but  stone  and  gravel  when  these  are  small  enough.  In  placer- 
mining  streams  of  water  much  more  powerful  are  directed  against 
hill-slopes  of  earth  and  stone,  which  disappear 
Breaking  Earth  a  great  deal  faster  than  by  means  of  spades 
for  Removal  an^j  shovejs>  One  of  our  Northwestern  rail- 
roads runs  for  some  miles  along  the  base  of  a 
steep  ridge,  from  which  at  times  heavy  -rains  wash  down  masses 
of  earth,  sand  and  gravel  to  the  track.  A  powerful  steam  pump 
forcing  a  stream  through  hose  removes  the  obstructions  from  the 
line  with  amazing  rapidity.  Work  a  good  deal  commoner  and 
vastly  more  important  consists  in  taking  a  process  begun  by  na- 
ture and  carrying  it  many  steps  further,  so  as  to  break  up  masses 
of  earth  again  and  again.  The  plow,  the  harrow,  the  sharp- 
toothed  cultivator,  divide  and  subdivide  the  soil  of  farm  and  gar- 
den so  as  to  offer  rootlets  new  surfaces  at  which  rain  may  be 
drunk  in  with  its  nourishing  food.  When  a  garden  patch  is  to 
be  fertilized  by  bones,  these  serve  best  when  reduced  to  meal, 
so  as  to  be  quickly  and  widely  absorbed. 

In   earth-sculpture    one    of    the   busiest    agents    is    the    wind, 
especially  as  it  seizes  ocean  waves  and  dashes  them  upon  beach 
and  cliff,  grinding  large  stones  to  pieces,  and 
W w*  °d  *  reducing  these  at  last  to  mere  pebbles  and  sand. 

On  land  the  gales  take  hold  of  sand  and  dust 
with  effects  even  more  telling:  sand  flung  against  the  hardest 
quartz  or  granite  will  bring  it  to  powder  at  last.  Sand  dunes, 
shifting  under  the  stress  of  high  winds,  have  spread  desolation 
around  Provincetown,  Massachusetts,  and  in  many  another  region 
once  fertile  enough.  This  process  of  nature  immemorially  old  has 
been  copied  in  modern  invention,  by  the  sandblast  devised  by  the 
late  General  Tilghman  of  Philadelphia.  In  its  simplest  form, 
sand  from  a  hopper  falls  in  a  narrow  stream  upon  window  panes, 
glassware  and  the  like,  to  be  roughened  except  where  protected 
by  a  paper  pattern.  Had  sandstone  in  lumps,  as  large  as  playing 
marbles,  been  dropped  on  the  glass,  there  would  have  been  harm- 
ful fracture;  as  each  particle  of  sand  weighs  too  little  in  pro- 


DUST  125 

portion  to  its  striking  surface  to  do  more  than  detach  a  tiny  chip, 
we  have  a  bombardment  wholly  useful. 

Primitive  man  achieved  an  incomparable  triumph  when  first  he 
kindled  fire  by  swiftly  twirling  one  dry  stick  upon  another,  drop- 
ping the  tiny  sparks  on  finely  divided  tinder, 
quick  to  catch  fire  because  it  presented  much      Dimensions  in 

-  .  Ignition. 

surface  to  the  air.  Peat,  a  fuel  common  in 
many  parts  of  the  world,  easily  dug  from  bogs  and  marshes,  can 
be  readily  dried  if  'chopped  into  fragments  and  exposed  to  the 
wind  in  open  sheds.  Charcoal  easily  produced  from  wood  of  any 
kind,  is  often  used  to  absorb  harmful  gases  in  boxes  of  preserved 
meats  and  in  household  refrigerators.  Its  effectiveness  is  due  to 
its  minute  pores,  presenting  as  they  do  a  vast  area  of  capillary 
attraction.  Charcoal,  of  course,  burns  faster  when  powdered 
than  when  unbroken ;  and  gunpowder,  into  which  charcoal  largely 
enters,  is  molded  into  cakes  either  big,  if  it  is  to  burn  somewhat 
slowly,  or  is  pressed  into  fine  grains,  when  an  explosion  all  but 
instantaneous  is  desired. 

Common  dust  surrounds  us  always,  entering  the  tiniest  chink 
of  wall  and  ceiling  to  show  its  path  by  a  defacing  mark.    In  dry 
seasons  it  abounds  to  a  distressing  degree,  and 
accumulates    rapidly    at    considerable    heights      Dust  common 
from  the  ground.     Observe  a  roof  of  the  kind     and  Uncommon, 
that  slopes  gradually  toward  the  street,  with  a 
trough  running  along  the  cornice  to  carry  off  the  rain  or  melted 
snow.    When  such  a  gutter  is  undisturbed  for  a  few  months  it 
is  clogged  with  mud  due  to  the  dust  which  has  been  lifted  by 
winds  to  the  roof,  and  swept  by  successive  showers  into  the 
gutter.     Dust  particles,  because  they  have  so  much  surface  for 
their  mass,  are  readily  caught  up  and  borne  to  heights  far  ex- 
ceeding those  of  the  highest  roofs.    The  terrific  explosion  of  the 
volcano  at  Krakatoa,  in  the  Sunda  Strait  of  Java  in  1883,  shot 
more  than  four  cubic  miles  of  dust  into  the  upper  levels  of  the 
atmosphere,   encircling  the   globe  with  particles  which    fell   so 
slowly  as  for  months  to  color  the  sunsets  of  New  York  and 
Canada,  ten  thousand  miles  away. 

Wheat  like  other  grain  is  combustible,  hence  as  food  it  sustains 


126  SIZE 

bodily  warmth.    Under  stress  of  necessity  wheat,  corn,  and  barley 
have  been  burned  as  fuel  when  coal  and  wood  have  been  lacking. 
In  the  process  of  flour-making  wheat  is  ground  to  a  powder  so 
fine  that  when  its  particles  are  diffused  through  the  air  of  a  mill, 
there  is  a  liability  to  explosion  because  the  in- 
Inflammable        flammable  dust  comes  so  near  to  contact  with 
the  atmospheric  oxygen  that  at  any  moment 
they  may  unite.    At  Minneapolis,  frightful  disasters  were  brought 
about  in  this  way  until  specially  devised  machines  removed  the 
dust.    In  coal  mines,  too,  coal  may  fill  the  air  with  a  dust  so  fine 
that  explosions  take  place,  with  serious  loss  of  life.    In  Austria  it 
has  been  found  that  the  fineness  of  the  dust  has  more  to  do  with 
the  violence  of  such  explosions  than  has  the  chemical  composition 
of  the  particles. 

In  mining,  let  us  observe,  the  whole  round  of  work  consists  in 
separations  which  bring  masses  from  bigness  to  smallness,  again 
and  again.  First  of  all  the  solid  walls  and  floors  are  broken  up 
by  pick,  or  drill,  or  powder,  or  all  together.  Iron  ores  as  hoisted 
to  the  surface  of  the  earth  are  taken  to  breakers  which  crush  them 
into  pieces  suitable  for  the  blast  furnace.  When  the  ores  carry 
gold,  copper,  lead,  or  tin,  this  crushing  is  followed  by  stamping 
to  facilitate  the  final  process  by  which  metal  is  separated  from 
worthless  rock. 

Spinning  and  weaving,  remote  as  they  are  from  mining,  are 
equally  subject  to  the  law  of  surfaces  and  volumes.    It  is  in  fur- 
thering adhesion  by  giving  their  thread  a  multi- 
Dimensions  in       plied    surface    that    the    spinner    and    weaver 
Woven  Fabrics,      manufacture  cloth  at  once  strong  and  durable. 
The  best  linens  and  silks  are  spun  in  exceed- 
ingly fine  threads;  canvases  and  tweeds  have  threads  compara- 
tively coarse.    From  the  cut  edge  of  a  piece  of  fine  silk  fabric  it 
is  hard  to  pull  out  a  lengthwise  thread ;  the  task  is  easy  with  sail- 
cloth. 

From  observation  let  us  turn  to  experiment  as  we  further  con- 
sider the  law  of  size.  Inventors,  especially  young  inventors,  are 

apt  to  underrate  the  difficulty  of  supplying  an 
The  Dimensions        f,  .  «  ,  J..  *  i.      ,    . 

of  Models  want  in  a  new  and  successful  way.    In  their 

enthusiasm  they  may  lose  sight  of  principles 
which  oppose  their  designs,  as  for  instance,  the  rules  which  gov- 


PROFIT  IN  BIGNESS  127 

ern  the  plain  facts  of  dimensions.  Mr.  James  B.  Eads,  in  planning 
his  great  bridge  at  St.  Louis,  chose  three  spans  instead  of  one 
span.  Why?  For  the  simple  reason  that  if  built  in  one  span 
the  weight  of  the  bridge  would  have  been  twenty-seven  times 
that  of  a  span  one-third  as  long,  while  only  nine  times  as  strong, 
assuming  that  both  structures  had  the  same  form.  Two  pieces  of 
rubber  will  clearly  exhibit  the  contrast  in  question.  One  piece 
is  three  feet  long,  one  inch  wide,  one  inch  thick ;  the  other  piece 
is  one  foot  long,  and  measures  in  width  and  thickness  one-third 
of  an  inch.  Placing  each  on  supports  at  its  ends  we  see  how 
much  more  the  longer  strip  sags  than  the  shorter.  The  longer 
has  twenty-seven  times  the  mass  of  the  other,  but  only  nine  times 


The  upper  strip  of  rubber  is  thrice  as  long,  wide  and  deep  as  the 
lower,  which  sags  less. 


its  strength.  Many  an  inventor  has  ignored  this  elementary  fact 
and  built  a  model  of  a  bridge,  or  roof,  which  has  seemed  ex- 
cellent in  the  dimensions  of  a  model,  only  to  prove  weak  and 
worthless  when  executed  in  full  working  size. 

We  have  glanced  at  a  few  cases  of  invention  where  it  has  been 
remembered  that  the  larger  a  mass  of  given  shape  the  less  its 
surface  as  compared  with  its  bulk.    Let  us  note 
how  this  rule  enters  into  the  tasks  of  the  ship-      Why  Big  Ships 
builder.    We  take  a  narrow  vial  of  clear  glass,  arc  Best- 

nearly  fill  it  with  white  oil  or  glycerine,  cork 
it,  and  shake  it  smartly.  Holding  the  vial  upright  we  observe 
that  the  largest  bubbles  of  imprisoned  air  come  first  to  the  top 
of  the  liquid,  because  in  comparison  with  bulk  they  have  least 
surface  to  be  resisted  as  they  rise.  For  a  parallel  case  we  visit 
the  docks  of  New  York,  and  note  a  wide  diversity  of  steamers. 
Here  is  the  "Baltic,"  of  the  White  Star  Line,  with  a  length  of 
726  feet,  and  a  displacement  of  28,000  tons.  Less  than  a  mile 


128 


SIZE 


away  is  a  small  steamer  trading  to  Nova  Scotia,  having  a  length 
of  but  260  feet,  and  a  displacement  of  only  1,000  tons  or  so.  We 
recognize  at  once  why  the  quickest  ships  are  always  among  the 
biggest.  It  is  simply  the  case  of  bubbles  small 
and  great  over  .again;  the  biggest  vessels  in  pro- 
portion to  size  have  least  surface  whereat  to  re- 
sist air  and  sea,  so  that  they  can  run  fastest  be- 
tween port  and  port.  As  with  ships,  so  with  their 
engines ;  economy  rests  with  bigness ;  the  largest 
engines  have  proportionately  least  surface  at  which 
to  lose  heat  by  radiation  or  by  contact,  or  for  re- 
sistance by  friction  as  they  move.  Indeed  in  de- 
signing ocean  steamers  of  the  greyhound  type  it 
is  imperative  that  the  utmost  possible  dimensions 
be  adopted.  The  "Mauretania"  and  the  "Lusi- 
tania"  just  built  for  the  Cunard  Company,  to  be 
driven  by  steam  turbines  at  25  knots  an  hour,  will 
each  demand  70,000  horse-power.  They  are  790 
feet  in  length  over  all,  88  feet  in  beam,  60^/2  feet 
in  depth,  with  a  displacement  of  45,000  tons.  Mr. 
William  F.  Durand,  in  his  work  on  the  resistance 
and  propulsion  of  ships,  considers  three  vessels 
less  huge  and  swift  than  these  Cunarders  and 
able  to  cross  the  Atlantic  in  say  seven  days.  The 
5,ooo-ton  ship  could  barely  make  the  trip  with  no 
Air  bubbles  rising  -arg°  at  all,  a  i6,ooo-ton  ship  would  be  able  to 
in  oil.  carry  3,000  tons  of  freight,  while  a  2O,ooo-ton 

ship  could  carry  4,200  tons  of  cargo.  Burdens  of 
hull,  machinery,  and  coal  do  not  increase  as  rapidly  as  gross 
tonnage  when  the  dimensions  of  a  ship  are  enlarged. 

Now  we  begin  to  realize  how  great  is  the  boon  of  cheap  steel, 
much  stronger  than  iron,  of  which  ships  and  engines  may  be  built 
bigger  than  at  any  earlier  period.  Steel  of 
great  strength  has  made  feasible,  too,  the  Eiffel 
Tower  in  Paris,  nearly  a  thousand  feet  tall,  the 
office-buildings  of  New  York  thirty  stories  in  height,  and  steel 
will  soon  cross  the  St.  Lawrence  near  Quebec  with  a  single  span 
of  1,800  feet.  In  1904,  at  Schenectady,  N.  Y.,  the  New  York 


Bigness  Needs 
Strong  Materials. 


MECHANICAL  FLIGHT  129 

Central  &  Hudson  River  Railroad  Company  began  comparisons 
between  an  electric  locomotive  of  201,000  pounds,  shown  opposite 
page  476,  and  a  steam  locomotive  so  huge  that  with  its  tender  it 
weighed  no  less  than  342,000  pounds.  Steel,  as  the  material  of 
engines  and  tools  of  all  sorts  enables  us  to  build  in  dimensions 
bolder  than  ever  before;  or,  if  old  dimensions  are  not  surpassed, 
we  are  free  to  employ  velocities  quite  out  of  the  question  with 
iron. 

It  is  a  long  time  since  adventurers  first  entrusted  themselves  to 
floating  logs,  afterward  tied  together  as  rafts,  and  slowly  im- 
proved until  they  became  boats  moved  by  paddles  or  oars.  Thus 
far  little  else  than  failure  has  attended  the  inventors  who  have 
sought  to  navigate  the  air  as  easily  as  river,  lake  or  sea.  A  stride 
toward  success  was  however  distinctly  taken  when  the  strongest 
known  alloys,  those  of  steel  and  nickel,  gave  the  aeronaut  a 
stronger  boiler,  pound  for  pound,  than  he  ever  had  before,  with 
wings  lighter  in  proportion  to  their  power  than  those  of  earlier 
experiments.  Let  the  burden  of  his  apparatus  be  further  re- 
duced, and  by  one-half;  then  we  may  expect  him  to  reign  in  the 
air  as  securely  as  the  sea-gull.  The  original  resource  of  the  aero- 
naut, his  balloon,  suffers  from  a  permanent  disability.  Air  has 
but  y770  the  specific  gravity  of  water,  so  that  a  balloon  must  be 
enormous  to  have  any  carrying  capacity  worth  while.  And  what 
would  become  of  a  balloon,  its  rudder  and  ropes,  if  caught  in  a 
hurricane  of  eighty  miles  an  hour  ? 

Let  the  aeronaut  continue  his  wistful  and  envious  gaze  at  the 
birds  in  the  sky  while  we  turn  our  attention  to  mother  earth,  there 
to  note  how  every  day  trade  surrounds  us  with 

further  illustrations  of  the  law  of  size,  of  the  A  Store 

i  .  ,  11-  11  T  Continues  the 

gams  which  may  attend  bigness.     We  enter  a  Lesson 

department  store,  displaying  a  varied  stock  of 
foods,  clothing,  shoes,  furniture,  and  so  on.  As  we  cast  our  eyes 
about  its  counters,  shelves,  and  floor  we  see  cans  of  vegetables, 
fruit,  and  fish ;  jars  of  olives  and  vinegar ;  boxes  of  rice,  soap  and 
crackers;  paper  sacks  of  flour  and  meal.  Outside  the  door  are 
piled  kegs,  barrels,  and  packing  cases.  Plainly  the  cost  of  paper, 
glass,  tin,  and  lumber  for  packages  must  levy  a  large  tax  on  re- 
tailing. Once  more  is  recalled  our  old  lesson  with  the  inch- 


130  SIZE 

cubes ;  the  bigger  a  jar,  box,  or  sack,  the  less  material  it  needs  in 
proportion  to  its  capacity.  Wholesale  packers  of  merchandise 
save  money  as  they  form  packages  of  the  largest  size.  The  con- 
tents of  each  box,  crate,  and  sack  tell  the  familiar  story  once 
again.  The  coffee  is  ground  from  the  bean  that  it  may  be  readily 
infused  in  the  coffee-pot;  wheat  is  reduced  to  flour,  oats  to  fine 
meal,  that  they  may  be  quickly  cooked;  sugar  is  crushed  that  it 
may  rapidly  dissolve  in  the  tea  cup.  This  very  task  began  long 
ago  with  the  mastication  of  food  by  the  teeth,  diminishing  the  size 
of  morsels  while  moistening  them  for  digestion  before  they 
reached  the  stomach. 

During  a  visit  to  the  country  one  summer,  we  observed  new 
examples  of  our  familiar  rule.     When  we  compared  the  dimen- 
sions of  a  small  sectional  cabin  with  those  of 
Umn^r     °  *  ay      a  large  house,  we  saw  the  principal  reason  why 
the  cabin  was  hard  to  keep  cool  in  July,  and 
hard  to  keep  warm  in  December.     We  noticed  tasks  which  de- 
pended upon  giving  wood,  cloth  or  other  material  as  much  sur- 
face as  possible,  whether  new  forms  were  like  old  ones  or  not.    A 
neighboring  sawmill  was  busy  cutting  up  logs  into  thin  boards; 
these  were  piled  in  open  tiers,  so  that  the  drying  winds  might 
speedily  finish  their  work.    In  the  same  way  we  noted  a  laundress 
spreading  out  by  itself  each  table-cloth  and  apron  fully  to  catch 
the  wind,  instead  of  leaving  the  linen  as  a  solid  heap  in  her 
basket,  where  only  the  edges  would  be  dried.     When  the  farm- 
hands went  haymaking  they  followed  the  same  rule ;  they  tedded 
out  their  gavels  to  give  them  the  utmost  supply  of  sun  and  air; 
when  all  was  as  dry  as  a  bone  they  reared  a  haycock  of  compact 
form  so  as  to  expose  the  least  possible  surface  to  rain  and  snow. 
So  much  for  things  to  be  observed  in  a  country  ramble,  in  a  city 
store,  or  at  the  docks  of  a  busy  port.    Apart  from  all  such  things 
is  a  world  unseen,  standing  beneath  the  visible 
Molecular  world,   and   equally   worthy   of   study.      Here 

knowledge  is  based  upon  inferences,  upon  what 
lawyers  call  circumstantial  evidence.  The  chemist  by  means 
purely  indirect  studies  the  molecule  and  the  atom,  objects  that  far 
elude  his  microscope.  A  molecule  is  a  part  of  a  compound  so 
small  that  it  cannot  be  divided  without  becoming  something 


UNITS  OF  CHEMISTRY  131 

simpler.  Thus  a  sugar  molecule  is  made  up  of  carbon,  hydrogen, 
and  oxygen  atoms;  were  these  disjoined,  the  sugar,  as  such, 
would  cease  to  be,  just  as  a  brick  wall  no  longer  exists  when  its 
bricks  and  their  several  slices  of  mortar  are  parted  from  one  an- 
other as  separate  units.  Small  as  molecules  are  they  have  not 
escaped  the  measuring  rod  of  the  physicist.  Some  years  ago  Lord 
Kelvin  experimentally  arrived  at  the  estimate  that  the  average 
molecule  has  a  diameter  of  1/760,000,000  inch.  Such  molecules 
when  compared  with  masses  of  like  form,  and  of  a  diameter  of 
one  inch,  have  760,000,000  times  as  much  surface.  In  the  trans- 
mission of  motion,  with  adhesion  in  play,  surfaces  count  for  much, 
as  when  a  wheel  in  motion  is  brought  into  contact  with  a  wheel  at 
rest.  Here  may  be  an  explanation  of  why  electricity  is  conducted 
through  a  wire  with  a  velocity  far  exceeding  any  speed  we  can 
mechanically  impress  upon  the  metal,  because  the  molecules  con- 
cerned have  incomparably  more  surface  than  the  wire  as  a  mass. 
By  virtue,  also,  of  its  minuteness  the  molecule  as  a  reservoir  of 
energy  can  far  excel  a  mass  of  visible  dimensions.  Let  us  com- 
pare two  rotating  spheres,  one  of  them  of  seven 
times  the  radius  of  the  other.  We  spin  both  at  Rc£j[Jroir8 °* 
the  same  peripheral  rate,  and  gradually  increase 
this  speed :  which  will  be  the  first  to  break  apart  under  centrifugal 
strain  ?  The  larger,  and  why  ?  Because  the  cohesion  of  a  sphere 
is  in  proportion  to  the  area  of  its  great  circle,  which  varies  as  the 
square  of  its  diameter,  while  centrifugal  strain  under  swift  rota- 
tion varies  as  the  cube  of  that  diameter,  or  as  the  volume  of  the 
sphere.  From  this  it  follows  that  we  may  safely  spin  our  small 
sphere  with  a  circumferential  velocity  seven  times  that  given  the 
large  sphere ;  therefore  as  containers  of  energy  small  spheres  are 
more  effective  than  large,  and  this  inversely  as  their  diameters. 
Spheres,  or  bodies  of  any  other  form,  if  reduced  in  dimensions  to 
i/76o,ooo,oooth,  would  as  reservoirs  of  energy  gain  760,000,000- 
fold.  Thus  we  open  a  door  of  explanation  regarding  the  stupend- 
ous contrast  between  chemical  energy  and  mechanical  work. 
Chemical  processes  are  exerted  by  molecules  and  atoms,  mechan- 
ical work  takes  place  among  masses  comparatively  enormous  in 
bulk.  It  may  require  a  hundred  blows  from  a  ponderous  steam 
hammer  to  raise  the  temperature  of  an  iron  bar  ten  degrees ;  that 


132 


SIZE 


bar  melts  in  ten  seconds  when  plunged  into  a  flame  produced  by  a 
few  ounces  of  hydrogen  and  oxygen  gases. 

Recent  experiments  by  Professor  Joseph  J.  Thomson  point  to 
the  probability  that  the  atom  of  the  chemist  while  a  unit,  is  in  part 
built  of  electrons  each  but  one-thousandth  part  the  size  of  a 
hydrogen  atom.  An  electron,  by  virtue  of  its  infinitesimal  minute- 
ness, becomes  able  to  hold  proportionately  much  more  energy  than 
is  possible  to  an  atom  moving  as  a  whole.  This  brings  us  to  some 
comprehension  of  the  astonishing  powers  of  radium,  an  element 
which  maintains  itself  at  a  temperature  3°  to  5°  Centigrade  higher 
than  that  of  its -surroundings,  probably  through  the  collision  with- 
in each  atom  of  its  component. parts. 

Water-waves  as  they  strike  a  shore  or  the  sides  of  a  basin  exert 
a  thrust,  or  a  repelling  action,  which  may  easily  be  observed. 
That  sound-waves  act  in  similar  fashion  is 
proved  by  a  little  sound-mill  devised  in  1883  by 
Professor  V.  Dvorak,  of  the  University  of 
Agram  in  Austria.  It  consists  of  four  vanes, 
each  a  small  card  slighty  curved,  mounted  on  a  spindle.  In  a 
sounding-box  nearby  is  a  tuning-fork  which  may  be*  struck  through 
its  stem  F.  A  Helmholtz  resonator  has  its  wide  opening  turned 


Repulsion  by 

Sound  and 

Light. 


Dvorak  Sound-mill. 

toward  this  box,  its  narrow  opening  toward  the  mill.  A  stroke  on 
the  tuning-fork  emits  vibrations  which  send  tiny  jets  of  air  against 
the  sails  of  the  mill,  which  accordingly  rotate  at  a  pace  propor- 
tionate to  the  loudness  of  the  sound. 


LIGHT  DEFLECTS  DUST 


133 


Professor  Ernest  F.  Nichols  of  Columbia  University,  New 
York,  and  Professor  Gordon  F.  Hull  of  Dartmouth  College,  in 
the  Journal  of  Astrophysics,  Chicago,  June,  1903,  describe  their 
apparatus  for  measuring  the  radiation  pressure  of  light,  a  phe- 
nomenon analogous  to  that  studied  by  Professor  Dvorak  in  the 
field  of  sound.  In  the  same  number  of  that  Journal  they  detail  an 
experiment  to  show  light  exerting  a  driving  action  on  very  tenuous 
particles.  They  burned  a  puff  ball 
of  lycoperdon  to  charcoal  spherules 
of  about  one-sixth  the  specific  grav- 
ity of  water.  These  spherules,  with 
some  fine  emery  sand,  they  placed  in 
a  glass  tube  shaped  like  an  hour- 
glass; this  tube  was  then  exhausted 
of  its  gases  until  a  mere  fraction  re- 
mained which  could  not  be  removed. 
With  the  sand  and  charcoal  in  its 
upper  half  the  tube  was  held  upright, 
while  a  beam  of  light  twenty  to  forty 
times  as  strong  as  sunshine  was 
thrown  on  the  tube  just  below  its 
neck.  By  tapping  the  glass  a  stream 
of  sand  and  charcoal  descended;  the 
sand  fell  through  the  beam  without 
deflection ;  the  charcoal  particles  were 
driven  away  from  the  stream  as  they 
fell  through  the  light.  Part  of  this  A  beam  of  light  deflects  dust, 
effect  was  due  to  the  slight  remnant 

of  gas  left  in  the  tube  which,  warmed  by  the  light,  produced  a 
motion  resembling  that  of  a  Crookes'  radiometer;  the  remainder 
of  the  effect  was  caused  by  the  drive  or  repulsion  of  the  luminous 
beam.  It  is  argued  that  this  repulsion  by  light  is  probably  one  of 
the  causes  why  the  sun  seems  u  drive  away  the  tail  of  a  comet, 
whose  particles  being  extremely  minute  have  much  surface  and 
little  bulk,  so  that  they  are  more  repelled  by  the  light  of  the  sun 
than  they  are  attracted  by  his  mass.  To  approach  cometary  con- 
ditions in  an  experiment  it  would  be  necessary  to  intensify  sun- 
light no  less  than  i, 600- fold,  because  on  the  surface  of  the  earth 


-  :.-•.«>:-"•"     II 


134  SIZE 

its  own  gravitation  is  1, 600  times  greater  than  that  which  is  there 
exerted  by  the  sun. 

The  law  that  a  given  shape  when  enlarged  increases  much  more 
^apidly  in  volume  than  in  surface  has,  in  our  brief  survey,  bound 

together  a  wide  diversity  of  facts  in  astronomy, 

A  Law  as  a          geology,    geography,    navigation,    engineering, 

Binding  Thread,     mechanics,   physics,   and   chemistry.     A   good 

many  times  I  have  brought  it  before  young 
folks  as  a  means  of  linking  together  everyday  observations  and 
principles  of  sweeping  comprehensiveness.  Boys  and  girls  are 
apt  to  think  that  there  is  a  formidable  barrier  between  science  and 
common  knowledge.  No  such  barrier  exists.  The  sun,  his 
planets  and  their  moons;  the  forces  which  carve  mountains  and 
valleys;  the  arts  of  shipbuilders,  of  designers  of  bridges,  office- 
buildings,  and  lighthouses;  the  plans  of  the  inventors  of  ma- 
chinery ;  the  rules  discovered  by  investigators  who  pass  from  ap- 
pearances to  the  underlying  reality  of  molecule  and  atom,  are  all 
within  the  sway  of  the  elementary  law  we  have  been  studying. 
There  is  a  gain  in  thus  pursuing  a  connecting  thread  of  classifica- 
tion, conferring  order  as  it  does  on  what  might  else  be  an  assem- 
blage of  things  collected  at  random.  A  law  such  as  that  of  size 
links  into  unity,  and  fastens  in  the  memory  a  vast  array  of  ob- 
servations and  experiments  which  otherwise  would  have  no  asso- 
ciating tie,  no  common  illumination. 


CHAPTER  XI 
PROPERTIES 

Food  nourishes  .  .  .  Weapons  and  tools  are  strong  and  lasting  .  .  .  Goth- 
ing  adorns  and  protects  .  .  .  Shelter  must  be  durable  .  .  .  Properties 
modified  by  art  ...  High  utility  of  the  bamboo  .  .  .  Basketry  finds 
much  to  use  .  .  .  Aluminium,  how  produced  and  utilized  .  .  .  Unwel- 
come qualities  turned  to  profit  .  .  .  Properties  long  worthless  are  now 
gainful  .  .  .  Properties  may  be  created  at  need. 

MATERIALS  are  valued  for  their  properties  as  well  as  their 
forms.  We  now  pass  to  a  rapid  survey  of  properties  as 
observed  in  gifts  of  nature,  as  modified  by  art,  as  turned  to  ac- 
count in  many  ingenious  ways,  as  studied  by  the  investigators  who 
would  fain  know  in  what  particulars  of  ultimate  form,  size  and 
motion,  properties  may  really  consist. 

We  go  to  market  with  a  few  different  -coins :  one  of  them  is 
worth  a  hundred  times  as  much  as  another  of  about  the  same  size, 
because  gold  is  more  beautiful  than  nickel,  does  not  tarnish,  may 
be  hammered  into  leaves  of  extreme  thinness,  or  unites  with 
copper  as  an  alloy  which  withstands  abrasion  for  vears  after  it 
leaves  the  mint.  When  we  build  a  house  we  wish  strength  in  its 
foundation  and  walls,  so  we  pay  a  higher  price  for  granite  than 
for  limestone;  and  choose  for  joists,  floors  and  rafters  well 
seasoned  wood  in  preference  to  newly  sawn  lumber  liable  to 
warp  and  crack  with  heat  in  summer,  with  cold  in  winter.  So 
with  raiment :  silk  is  preferred  to  cotton  or  wool  because  hand- 
somer, stronger,  more  lasting.  But  food  comes  before  shelter, 
raiment  or  any  other  need  of  mankind,  and  qualities  of  nourish- 
ment and  palatability  mark  off  nuts,  fruits,  grain  and  roots  as 
suitable  for  food.  In  this  regard  all  living  creatures  exercise 
discrimination  under  penalty  of  death. 


135 


136  PROPERTIES 

A  score   of  sparrows   are   flitting  about   a   door-yard;   strew 
a  handful  of  crumbs  on  the  gravel  before  them;  at  once  the 

birds  begin  picking  up  the  bread,  leaving  the 
Food.  gravel   alone.      They   know   crumbs,    good   to 

eat,  from  stone,  not  good  to  eat.  The  earliest 
races  of  men,  immeasurably  higher  than  birds  in  the  scale  of 
life,  have  eaten  every  herb,  root,  grass,  and  fruit  they  could  find. 
Experiment  here  was  as  wide  as  the  world,  and  bold  enough  in 
all  conscience.  In  many  cases  new  and  delicious  foods,  thor- 
oughly wholesome,  were  discovered.  At  other  times,  as  when 
the  juice  of  the  poppy  was  swallowed,  sleep  was  induced,  with 
a  hint  for  the  escape  from  pain  in  artificial  slumber.  In  less 
happy  cases  the  new  food  was  poisonous ;  yet  even  this  quality 
was  pressed  into  service.  In  Mendocino  County,  California,  to 
this  day,  the  Indians  throw  soap  root  and  turkey  mullein,  both 
deadly,  into  the  streams ;  the  fish  thus  killed  are  eaten  without 
harm.  These  same  Indians  make  acorns  and  buckeye  horse 
chestnuts  into  porridge  and  bread,  pounding  the  seeds  into  a 
fine  flour  and  washing  out  its  astringent  part  with  water.  These 
and  other  aborigines  use  for  food  and  industry  many  plants 
neglected  by  the  white  man,  taking  at  times  guidance  from  the 
lower  animals.  One  of  the  early  explorers  of  South  Africa,  Le 
Vaillant,  says  that  the  Hottentots  and  Bushmen  would  eat  noth- 
ing that  the  baboons  had  left  alone.  Following  their  example 
he  would  submit  to  a  tame  baboon  new  plants  for  acceptance  or 
rejection  as  food. 

As  with  food  so  with  other  resources  almost  as  vital.     Long 
ago   the   savage   learned   that   hickory   makes    good   bows    and 

arrows,  that  as  a  club  it  forms  a  stout  and 
Weapons  and          t  TT       ,. 

Tools  lasting  weapon.     He  discovered,  too,  that  in 

these  qualities  soft  woods  are  inferior  and 
the  sumach  altogether  wanting.  Thus,  too,  with  the  whole 
round  of  stones  from  which  as  a  warrior  or  a  craftsman  he 
fashioned  knives,  chisels,  arrowheads,  axes;  it  was  important 
that  only  tough  and  durable  kinds  should  be  employed.  No 
lump  of  dry  clay  ever  yet  served  as  a  hammer  or  an  adze ;  happy 
were  the  tribes,  such  as  those  of  ancient  Britain,  who  had  at  hand 


MODIFICATIONS  137 

goodly  beds  of  flint  from  which  a  few  well  directed  blows  could 
furnish  forth  a  whole  armory  of  tools  and  weapons. 

In  the  eating  of  foods  simply  as  found,  in  the  use  of  materials 
for  clothing  or  building  just  as  proffered  by  the  hand  of  nature, 
much  was  learned  as  to  their  qualities ;  some 
were  found  good,  others  indifferent,  still  others  Properties 
bad.  Then  followed  the  art  of  modifying  these 
qualities,  so  as  to  bring,  let  us  say,  a  fibre  or  a  thong  from 
stiffness  to  pliability  and  so  make  it  useful  instead  of  almost 
worthless.  The  progress  of  man  from  downright  savagery  may 
be  fairly  reckoned  by  his  advances  in  the  power  to  change  the 
qualities  of  foods,  raiment,  materials  for  shelter,  tools,  and 
weapons.  These  arts  of  modification  go  back  very  far.  At 
first  they  may  have  consisted  simply  in  taking  advantage  of 
the  effects  of  time.  In  the  very  childhood  of  mankind  it  must 
have  been  noticed  that  fruit  harsh  and  sour  became  mellow  with 
keeping,  just  as  now  we  know  that  a  Baldwin  apple  harvested 
in  October  will  be  all  the  better  for  cellarage  until  Christmas, 
the  ripening  process  continuing  long  after  the  apple  has  left 
its  bough.  Grains  and  seeds  when  newly  gathered  are  usually 
soft  and,  at  times,  somewhat  damp ;  exposed  to  the  sun  and  dry 
air  for  a  few  days  they  become  hard  and  remain  sound  for 
months  or  even  years  of  careful  storage.  In  warm  weather 
among  many  Indian  tribes  such  food  was  almost  the  only  kind 
that  remained  eatable ;  all  else  went  to  swift  decay,  except  in 
parched  districts  such  as  those  of  Arizona,  so  that  roots,  fruits, 
the  flesh  of  birds,  beasts,  and  fish  had  to  be  consumed  speedily, 
a  fact  that  goes  far  to  account  for  the  gluttony  of  the  red  man. 
His  stomach  was  at  first  his  sole  warehouse;  that  filled,  any 
surplus  viands  went  to  waste.  In  frosty  weather  this  havoc 
ceased;  as  long  as  cold  lasted  there  was  no  loss  in  his  larder. 
A  few  communities,  as  at  Luray,  Virginia,  or  at  Mammoth  Cave, 
Kentucky,  in  their  huge  caverns  had  storehouses  which  would 
preserve  food  all  the  months  of  the  twelve.  In  New  Mexico 
and  other  arid  regions  the  air  is  so  dry  that  meat  does  not  fall 
into  decay.  How  it  was  discovered  that  smoke  had  equal  virtue 
we  know  not.  Probably  the  fact  came  out  in  observing  the 


138  PROPERTIES 

accidental  exposure  of  a  haunch  of  venison  as  the  reek  from  a 
camp-fire  sank  into  its  fibres.  Salt,  too,  was  early  ascertained 
to  have  great  value  in  preserving  food.  Suppose  a  side  of  buffalo, 
or  horse,  to  have  fallen  accidentally  into  brine  in  a  pool  or  kettle, 
and  stayed  there  long  enough  for  saturation,  its  keeping  sweet 
afterward  would  give  a  hint  seizable  by  an  intelligent  housewife. 
Preservation  by  burial  in  silos  began  in  times  far  remote,  and 
was  fully  described  by  Pliny  in  the  first  century  of  the  Christian 
era. 

The  skin  just  taken  from  a  sheep,  the  hide  when  removed  from 

an  ox,  are  both  as  flexible  as  in  life.     But  they  soon  stiffen  so 

as  to  be  uncomfortable  when  worn   as   gar- 

P^°,PT-ieS  in        ments.      Wetting  the   pelt   is   but   a   transient 
Clothing.  °  r  m 

resource ;  satisfactory,  because  lasting,  is  the 
effect  of  rubbing  grease,  fat,  or  oil  into  the  texture  of  the  hide. 
Peary  in  Greenland  found  that  pelts  in  small  pieces,  and  bird- 
skins,  were  softened  by  the  Eskimo  women  chewing  them  for 
hours  together. 

Wetting  was  as  notable  an  aid  to  handicraft  of  old  as  today. 
Boughs,  roots,  withes,  osiers,  or  the  stems  of  fibrous  plants,  when 
thoroughly  saturated  with  water  became  so  soft  as  to  be  easily 
worked,  yielding  strands,  as  in  the  case  of  hemp,  separated  from 
worthless  pulp.  Hence  the  basketmaker,  the  wattler,  the  builder, 
the  potter,  the  weaver  of  rude  nets  and  traps,  long  ago  learned 
to  wet  their  materials  to  make  them  plastic.  Take  now  the 
reverse  process  of  drying,  which  toughens  wood,  and  the  sinews 
used  as  primitive  thread.  Leaves  when  dried  become  hard  and 
brittle  of  texture,  hence  the  necessity  that  when  woven  and  inter- 
laced as  roofs  the  work  shall  promptly  follow  upon  gathering 
the  material.  In  plaiting  coarse  mats  and  sails  may  have  begun 
the  textile  art  which  to-day  gives  us  the  linens  of  Belfast,  the 
silks  of  Lyons  and  Milan. 

A  good  and  serviceable  imitation  of  silk  is  due  to  a  simple 
and  ingenious  treatment  of  cotton.  In  1845  J°hn  Mercer,  a 

Lancashire   calico  printer,   one   day  filtered   a 

solution   of   caustic   soda  through   a   piece   of 
an^Beautified.       cotton  cloth.     He  noticed  that  the  cloth,  as  it 

dried,  was  strangely  altered :  it  had  shrunk 
considerably  both  in  length  and  breadth,  had  become  stronger, 


STONE  AND  CLAY  139 

with  an  increased  attraction  for  dyes.  This  was  the  beginning  of 
the  mercerization  which  to-day  produces  cotton  fabrics  almost  as 
strong  and  handsome  as  if  silk.  The  cloth,  preferably  woven  of 
long  Sea  Island  staple,  is  immersed  in  a  solution  of  caustic  soda, 
and  afterward  washed  in  dilute  sulphuric  acid  and  in  pure  water. 
As  it  enters  the  caustic  bath  the  cotton  is  pure  cellulose,  as  it 
leaves  the  bath  the  fabric  is  hydrated  cellulose,  with  new  and 
valuable  properties.  The  structural  change  in  the  fibre  is  decided. 
The  original  filament  of  cotton  is  a  flattenc  !  tube,  the  sides  of 
which  are  close  together,  leaving  a  central  cavity  which  is  en- 
larged at  each  edge  of  the  surrounding  tube.  It  is  opaque  and 
the  surface  is  not  smooth.  The  fibre  has  also  a  slight  twist. 
The  tube  after  treatment  becomes  rounded  into  cylindrical  form ; 
its  cavity  is  lessened  and  the  walls  of  its  tube  thicken ;  the  sur- 
face becomes  smooth  and  each  fibre  assumes  a  spiral  form. 
Effects  like  these  of  mercerization  are  produced  in  paper  as  well 
as  in  cotton  cloth,  yielding  vegetable  parchment,  a  familiar 
covering  for  preserve  jars  and  the  like. 

Some  sandstones,  such  as  are  common  in  Ohio  and  Indiana, 
soft  when  hewn  in  the  quarry,  soon  harden  on  exposure  to 
wind  and  weather;  materials  of  this  kind  in 
early  times  afforded  shelter  more  lasting  than  Properties  in 
tents  of  boughs  or  hides.  But  the  building  Material* 
art  was  to  know  a  gift  vastly  more  importantx, 
when  an  artificial  mud  was  blended  of  clay  and  water,  with  a 
steady  improvement  both  in  the  strength  and  durability  of  the 
product.  It  was  a  golden  day  in  the  history  of  man  when  first 
a  clayey  paste  was  patted  into  a  pot,  a  bowl,  a  kettle :  then  was 
laid  the  foundation  of  all  that  the  potter,  the  brick  maker,  the 
tile  molder  have  since  accomplished.  Another  remarkable  dis- 
covery, needing  prolonged  and  faithful  experiment,  was  reached 
when  pottery  was  found  to  keep  its  form  better  when  broken 
potsherds  and  bits  of  flint  were  mingled  with  its  clay.  A  dis- 
covery of  equal  moment  was  that  of  mortar,  probably  approached 
in  the  daubing  of  mud  or  clay  into  chinks  of  stones,  with  the 
admixture  first  of  one  substance  and  then  another  until  the 
right  one  was  found,  and  the  binder  and  the  bound  became  of 
one  and  the  same  hardness.  The  Romans,  a  deliberate  race,  took 
two  years  in  making  a  batch  of  mortar;  that  bond  to-day  pro- 


140  PROPERTIES 

trudes  from  their  walls  as  more  resistant  to  the  tooth  of  time 
than  stone  itself. 

But  if  water  did  much  to  modify  properties,  flame  did  infi- 
nitely more.  A  block  of  blue  limestone  thrust  into  a  fire  was 
burned  to  whiteness,  and  became  lime,  which, 
Flame  and  Elec-  mixed  with  water,  proved  a  biting  compound 
of  slippery  feel,— an  alkali  indeed.  This  same 
wonderful  flame  caused  water  wholly  to  dis- 
appear from  a  heated  kettle ;  or  could  dissipate  almost  the  whole 
of  an  ignited  brand  or  lump  of  fat.  By  cooking  a  food,  it  gave 
a  new  relish  to  the  poorest  dish,  banished  from  such  a  root  as 
tapioca  its  poison,  and  when  a  yam  was  baked  it  remained  eatable 
for  a  twelvemonth.  Fire  enabled  man  to  melt  metals  as  if  they 
were  wax,  to  soften  iron  or  copper  which  a  deftly  swung  hammer 
shaped  as  he  willed.  Here,  too,  opened  the  whole  world  of 
chemistry,  one  of  its  first  gifts  the  power  to  take  an  ore  worthless 
when  unchanged,  and  gain  from  it  a  battle-axe,  a  knife,  an  arrow- 
head. Even  in  this  day  of  electricity  it  is  fire  which  the  en- 
gineer must  evoke  to  create  acids,  alkalis,  sugars,  alcohols,  from 
substances  as  different  from  these  as  iron  is  from  iron  ore. 

Electricity  as  a  modifier  of  properties  in  turn  throws  flame 
into  eclipse.  Take  an  example:  a  strip  of  ferro-nickel  is  fast 
dissolving  in  an  alkaline  bath;  attach  one  end  of  the  metal  to 
the  negative  pole  of  a  battery  or  a  dynamo,  the  other  end  to 
the  positive  pole;  at  once  solution  ceases  and  the  metal  begins 
to  pick  out  kindred  particles  from  the  bath,  adding  them  to  itself. 
Electricity  has  completely  reversed  the  wasting  process ;  what 
was  eaten  away  is  now  growing,  what  was  a  compound  is  now 
shaken  into  its  elements,  one  of  which  rapidly  increases  in  mass. 
Nothing  in  the  empire  of  heat  is  as  striking  as  this  process — 
familiar  in  renewing  the  energy  of  a  storage  battery.  Many  a 
union  or  a  parting  impossible  to  fire  is  wrought  instantly  by  the 
electric  wave. 

When  Mr.  Edison  devised  his  electric  lamp,  his  first  successful 
filaments  were  fibres  of  bamboo;  they  glowed  more  brilliantly 
than  anything  else  he  could  find,  they  were  tenacious  enough  to 
withstand  intense  heat  for  weeks  together.  A  single  gift  of 
nature,  such  as  the  bamboo,  may  be  so  many-sided  that  its  appli- 


THE  BAMBOO  141 

cations  greatly  enrich  human  life.    A  task  of  interest  would  be 
to  trace  the  vast  indebtedness  of  modern  science  and  art  to  car- 
bon, iron,  or  silver,  in  their  various  forms.     But  the  bamboo  is 
cheaper  and  more  abundant  than  any  of  these, 
so  that  it  will  be  worth  while  to  glance  at  the       The  Bamboo 
many  wants  it  has  satisfied,  at  the  creations  it     Rich  in  Utilities, 
has  suggested  to  ingenuity.    In  Ceylon,  India, 
China,  Japan,  the   Malay  archipelago,   it   is   the  chief   item   of 
natural  wealth,  the  main  resource  for  the  principal  arts  of  life. 
First  of  all  it  provides  food.     More  than  one  case  is  recorded 
where  its  abundant  seeds  have  staved  off  the  horrors  of  famine ; 
these  seeds,  too,  are  commonly  fermented  to  produce  a  drink 
resembling  beer.     Many  species  of  bamboo  have  shoots  which 
when  young  and  tender  are  a  palatable  and  nourishing   food. 
As  a  building  material  it  is  strong,  durable  and  easily  divided. 
Its  sizes  are  various  enough  to  provide  a  fishing-rod  for  a  boy, 
or  a  column  for  a  palace. 

"To  the  Chinaman,  as  to  the  Japanese,"  says  Mr.  Freeman- 
Mitford,  in  "The  Bamboo  Garden,"  "the  bamboo  is  of  supreme 
value;  indeed  it  may  be  said  that  there  is  not  a  necessity,  a 
luxury,  or  a  pleasure  of  his  daily  life  to  which  it  does  not 
minister.  It  furnishes  the  framework  of  his  house  and  thatches 
the  roof  over  his  head,  while  it  supplies  paper  for  his  windows, 
awnings  for  his  sheds,  and  blinds  for  his  verandah.  His  beds, 
tables,  chairs,  cupboards,  his  thousand  and  one  small  articles 
of  furniture  are  made  of  it.  Shavings  and  shreds  of  bamboo 
stuff  his  pillows  and  mattresses.  The  retail  dealer's  measure, 
the  carpenter's  rule,  the  farmer's  waterwheel  and  irrigating  pipes, 
cages  for  birds,  crickets,  and  other  pets,  vessels  of  all  kinds, 
from  the  richly  lacquered  flower-stands  of  the  well-to-do  gentle- 
man down  to  the  humblest  utensils  of  the  very  poor,  all  come 
from  the  same  source.  The  boatman's  raft,  and  the  pole  with 
which  he  punts  it  along;  his  ropes,  his  mat  sails,  and  the  ribs 
to  which  they  are  fastened;  the  palanquin  in  which  the  stately 
mandarin  is  borne  to  his  office,  the  bride  to  her  wedding,  the 
coffin  to  the  grave ;  the  cruel  instruments  of  the  executioner,  the 
beauty's  fan  and  parasol,  the  soldier's  spear,  quiver,  and  arrows, 
the  scribe's  pen,  the  student's  book,  the  artist's  brush  and  the 


142  PROPERTIES 

favorite  study  for  his  sketch;  the  musician's  flute,  the  mouth- 
organ,  plectrum,  and  a  dozen  various  instruments  of  strange 
shapes  and  still  stranger  sounds — in  the  making  of  all  these  the 
bamboo  is  a  first  necessity.  Plaiting  and  wickerwork  of  all  kinds, 
from  the  coarsest  baskets  and  matting  down  to  the  delicate  filigree 
which  encases  porcelain,  are  all  of  bamboo  fibre.  The  same 
material  made  into  great  hats  like  inverted  baskets  protects  the 
coolie  from  the  sun,  while  the  laborers  in  the  rice  fields  go  about 
looking  like  animated  haycocks  in  waterproof  coats  made  of  the 
dried  leaves  of  the  bamboo  sewn  together." 

In  North  America  the  Indians  have  had  no  such  resource  as 
the  bamboo,  but  with  tireless  sagacity  they  have  laid  under  con- 
tribution either  for  food  or  for  the  arts  every 

Materials  for  S1^  °*  tne  soil-  In  seeking  materials  for  bas- 
Basketry.  ketry,  for  example,  they  have  surveyed  the 

length  and  breadth  of  the  continent,  testing 
in  every  plant  the  qualities  of  root,  stem,  bark,  leaf,  fruit,  seed 
and  gum,  so  far  as  these  promised  the  fibres  or  the  dyes  for  a 
basket",  a  wallet,  a  carrier.  With  all  the  instinct  of  scientific 
research  they  have  sought  materials  strong,  pliant,  lasting  and 
easily  divided  lengthwise  for  refined  fabrics.  In  his  work  on 
"Indian  Basketry"  Mr.  Otis  T.  Mason  has  a  picture  of  a  bam- 
shi-bu  coiled  basket,  having  a  foundation  of  three  shoots  of 
Hind's  willow,  sewn  in  the  lighter  portions  with  carefully  pre- 
pared roots  of  kahum,  a  sedge;  while  its  ornamental  designs  are 
executed  in  roots  of  a  bulrush,  the  tsuwish.  Often  a  basket,  as 
in  this  case,  is  built  of  materials  found  miles  apart,  each  requiring 
patient  and  skilful  treatment  at  the  artist's  hands. 

A  few  trees,  the  cedar  in  particular,  lend  themselves  to  the 
needs  of  the  basketmaker  with  a  generous  array  of  resources. 
Mats  of  large  size  made  from  its  inner  bark  are  common  among 
the  Indians  of  the  Northern  Pacific  Coast.  From  the  roots  of 
the  same  tree  hats  are  woven  as  well  as  vessels  so  close  in  texture 
as  to  be  watertight.  When  the  roots  are  boiled  so  as  to  be 
readily  torn  into  fibres,  these  are  formed  into  thread,  either  woven 
with  whale-sinews  or  with  kelp-thread  as  warp.  Among  the 
handsomest  of  all  Indian  baskets  are  those  of  the  Porno  tribe, 
one  of  which  is  shown  on  page  109.  The  splints  for  their  creamy 


ALUMINIUM  143 

groundwork  are  made  from  the  rootstock  of  the  Car  ex  barbarae, 
which  are  dug  from  the  earth  with  clam  shells  and  sticks,  a 
woman  securing  fifteen  to  twenty  strands  in  a  day.  These  she 
places  in  water  over  night  to  keep  them  flexible,  and  to  soften 
the  scaly  bark  which  is  afterward  removed.  To  make  a  basket 
watertight  the  Indians  of  Oregon  weave  the  inner  bark  of  their 
maple  with  the  utmost  closeness.  In  other  regions  a  simpler 
method  is  to  apply  as  water-proofing  the  gum  of  the  pifion,  the 
resins  of  pines,  or  mineral  asphalt.  Equal  diligence  and  sagacity 
mark  the  Indians  as  users  of  stone.  The  Shastas  heat  a  stone  of 
such  quality  that  in  cooling  it  splits  into  flakes  for  weapons  and 
tools.  They  place  an  obsidian  pebble  on  an  anvil,  and  with  an 
agate  chisel  divide  it  as  they  wish ;  all  three  being  chosen  from  a 
vast  diversity  of  stones  which  must  have  been  tried  and  found 
inferior. 

From  Indian  handicrafts,  developed  by  aboriginal  skill,  patience 
and  good  taste  to  remarkable  triumphs,  let  us  turn  to  an  achieve- 
ment of  a  modern  chemist  who,  calling  electric- 
ity  to   his   aid,   bestowed   a   new   metal   upon      Aluminium  and 
industry,  making  possible  new  economies  in  a  Its  Uses, 

wide  sisterhood  of  arts.  Aluminium  was  dis- 
covered in  1828  by  Wohler,  a  German  chemist,  who  noted  its 
lightness,  toughness,  and  ductility.  At  the  Centennial  Exhibition 
at  Philadelphia,  in  1876,  a  surveyor's  transit  built  of  aluminium 
was  shown,  but  the  metal  at  that  time  was  six-fold  the  price  of 
silver,  so  that  the  instrument  for  some  years  remained  uncopied. 
Of  course,  engineers  and  mechanics  were  much  interested  in  a 
metal  only  about  one-third  as  heavy  as  brass  or  copper,  of  white 
lustre,  and  with  as  much  as  five-eighths  the  electrical  conductivity 
of  copper.  All  that  hindered  the  extensive  use  of  the  metal  was 
its  high  cost.  If  that  cost  could  be  lowered,  at  once  copper,,  and 
even  silver,  would  face  a  rival.  After  many  unsuccessful  because 
expensive  processes  for  obtaining  the  metal  had  been  devised, 
a,  method  was  found  at  once  simple  and  inexpensive. 

This  method  of  separating  aluminium  from  its  compounds 
was  devised  by  Charles  M.  Hall,  while  an  undergraduate  student 
at  Oberlin  College,  Ohio.  His  success  turned  on  his  knowledge 
of  the  properties  of  related  metallic  compounds.  He  recognized 


144  PROPERTIES 

the  probable  value  of  aluminium  in  the  arts,  could  it  be  produced 
in  large  quantity  at  low  cost.  He  believed  that  electrolysis  would 
prove  the  most  convenient,  thorough  and  inexpensive  method; 
but  there  was  at  that  time  no  process  known  by  which  it  could 
be  applied  to  this  element.  His  problem  was  to  find  a  form  of 
electrolyte  rich  in  aluminium  which  should  be  comparatively  easy 
to  separate  into  its  elements,  and  to  discover  a  substance  for  the 
solvent  which  should  prove  a  satisfactory  bath.  This  latter  sub- 
stance must,  furthermore,  be  a  good  conductor  of  electricity,  must 
readily  dissolve  the  proposed  electrolyte,  and  must  have  a  higher 
resistance  to  electrolytic  disruption  than  the  electrolyte.  To  dis- 
cover the  needed  substances  for  electrolyte  and  solvent  involved 
the  examination  of  all  available  compounds  of  aluminium,  the 
study  of  the  various  possible  solvents  for  the  compound  selected, 
and  the  determination  of  electric  conductivities.  By  virtue  of 
rare  familiarity  with  the  chemistry  and  physics  of  the  subject, 
with  the  properties  of  every  substance  concerned,  the  search  was, 
after  a  time,  rewarded  with  complete  success.  It  was  found  that 
bauxite — the  oxide  of  aluminium,  alumina,  in  fact — is  dissolved 
by  molten  cryolite,  the  double  silicate  of  aluminium  and  sodium, 
and  that  the  latter,  while  dissolving  the  bauxite  freely  and  serving 
as  an  ideal  solvent,  also  itself  breaks  up  under  the  action  of  the 
electric  current  at  a  much  higher  voltage  than  alumina.  So  far 
as  known,  these  are  the  only  substances  in  nature  which  stand 
to  each  other  in  such  relation  as  to  permit  the  commercial  pro- 
duction of  the  metal. 

Aluminium  as  constructive  material  has  disappointed  some  of 
its  earlier  advocates.  It  is  difficult  to  work,  gumming  the  teeth 
of  files  and  resisting  cutting  and  drilling  tools  by  virtue  of  the 
very  toughness  which  makes  it  desirable  for  tubes,  columns,  and 
the  like.  Its  excellences,  however,  are  manifold :  the  German 
army  on  investigation  found  that  helmets  of  aluminium,  as  light 
as  felt,  turned  the  glancing  impact  of  a  bullet.  For  soldiers'  use 
it  now  forms  not  only  helmets,  but  cooking  vessels,  cartridge 
cases,  buttons,  sword  and  bayonet  scabbards.  It  gives  the  photog- 
rapher as  well  as  the  surveyor  instruments  which  unite  strength 
with  lightness.  It  has  furthermore  the  quality  which  has  long 
given  value  to  the  lithographic  stone  of  Hohenlofen  in  Bavaria. 


ALUMINIUM  145 

Aluminium  takes  a  sketch  as  perfectly  as  does  the  stone,  with 
the  inestimable  advantages  that  the  metal  may  be  readily  curved 
for  a  cylinder  press,  that  it  is  compact  and  light  in  storage,  while 
without  the  brittleness  which  has  made  stone  so  costly  a  servant 
to  both  artists  and  printers.  To  produce  a  deep  color  from  stone 
it  may  be  necessary  to  print  one  impression  over  another  again 
and  again ;  from  aluminium  a  single  impression  is  enough,  as 
severe  pressure  may  be  safely  applied. 

Aluminium  has  so  great  an  affinity  for  oxygen  as  to  play  a 
conspicuous  part  in  the  metallurgy  of  other  metals.  In  the  cast- 
ing of  iron,  steel  or  brass,  the  addition  to  each  ton  of  two  to  five 
pounds  of  aluminium  greatly  improves  the  product ;  the  aluminium 
by  combining  with  the  occluded  gases  reduces  the  blowholes  and 
renders  the  molten  metal  more  fluid  and  therefore  more  homo- 
geneous. A  second  use  for  aluminium  turns  on  the  same  quality ; 
it  was  devised  by  Dr.  Goldschmidt  for  producing  high  tempera- 
tures, and  is  especially  useful  in  welding  steel  rails  and  pipes. 
A  mixture  of  iron  oxide  and  aluminium  finely  divided  is  ignited 
by  a  magnesium  ribbon ;  a  very  high  temperature  results  as  the 
aluminium  combines  with  the  oxygen  derived  from  the  iron  oxide. 

Aluminium  by  reason  of  its  lightness  occupies  a  large  field  in 
naval  and  military  equipments,  in  motor-car  construction,  and 
the  like,  where  the  reduction  of  weight  is  of  paramount  im- 
portance. For  cooking  utensils  the  use  of  aluminium  is  con- 
stantly extending;  the  metal  is  a  capital  conductor  of  heat,  is 
not  liable  to  deteriorate  in  use,  and  gives  rise,  if  dissolved,  to 
harmless  compounds.  The  chief  objection  to  aluminium  is  its 
low  tensile  strength,  which,  for  the  cast  metal  is  only  10,000  to 
16,000  pounds  per  square  inch.  An  improvement  is  effected  by 
adding  as  an  alloy  a  small  quantity  of  some  other  metal,  such  as 
nickel  or  copper.  When  one  part  of  aluminium  is  joined  with 
nine  parts  of  copper  we  have  aluminium  bronze,  the  strongest 
and  handsomest  of  copper  alloys,  much  resembling  gold  in  its 
lustre. 

Aluminium  is  finding  acceptance  as  an  electrical  conductor. 
An  installation  of  this  kind  in  Canada  unites  Shawinigan  Falls 
with  Montreal,  84.3  miles  distant.  Three  cables  are  employed, 
each  composed  of  seven  No.  7  wires.  The  total  loss  in  the 


146  PROPERTIES 

transmission  of  8,ooo-ho-rse  power,  at  50,000  volts  at  the  generat- 
ing station,  is  about  eighteen  per  cent.  Comparing  equal  con- 
ductors, in  round  numbers  the  cross-section  of  an  aluminium 
cable  is  one-and-a-half  times  that  of  a  copper  cable,  the  weight 
being  one-half  and  the  tensile  strength  three-quarters.  Every- 
thing considered  when  aluminium  is  2  i/io  the  price  of  copper, 
the  investor  is  equally  served  by  both  metals  as  conductors.  This 
is  true  only  where  the  conductors  are  bare.  Where  insulated 
cables  are  needed,  the  increased  diameter  of  an  aluminium  con- 
ductor entails  extra  cost  for  insulating  material. 

At  first  the  lightness  and  weakness  of  aluminium  were  much 
against  it;  these,  as  we  have  seen,  were  soon  overcome  by  alloy- 
ing the  metal  with  copper  or  nickel.  But  by 

Properties  at        giving  aluminium   forms   of  utmost   stiffness, 

Fare  Turned0™     b?  reinforcing  these   forms  with  steel  wires, 
Account.  the  metal  is  quite  strong  and  rigid  enough  for 

cups,  plates,  cameras  and  other  instruments 
for  which  lightness  is  most  desirable.  In  many  another  case  a 
material  or  a  characteristic  at  first  unwelcome  has  been  turned  to 
excellent  account.  Smokiness  in  a  fuel  is  not  a  quality  mentioned 
in  its  advertisements,  and  yet  smokiness  is  just  what  is  sought  in 
the  twigs,  stubble,  or  coals  set  on  fire  to  give  plants  a  cloud 
protecting  them  from  unseasonable  frosts.  It  is  astonishing  how 
little  fuel  will  serve  in  such  cases,  especially  if  the  atmosphere  is 
calm,  so  as  not  to  carry  the  smoke  where  it  is  not  needed.  Many 
another  instance  might  be  given  of  a  quality  objectionable  for 
one  service  and  then  turned  to  satisfying  a  new  want.  Some- 
times, too,  offensive  qualities  are  most  useful.  Illuminating  gas, 
as  at  first  manufactured,  had  a  distressing  odor,  which  gave 
prompt  and  unmistakable  notice  of  a  leak.  When  water  gas  came 
into  use,  most  harmful  when  inhaled,  the  chemists  were  puzzled 
to  know  how  to  give  it  an  offensive  smell;  they  found  that  a 
quality  long  complained  of  was  really  an  advantage  in  disguise. 

So  in  the  electrical  field,  when  an  unsought  quality  has  in- 
truded itself,  and  proved  unwelcome,  the  question  has  arisen,  what 
service  can  we  enlist  it  for?  Not  seldom  the  answer  has  been 
gainful  in  the  extreme.  Dr.  Oliver  J.  Lodge  tells  us  that  a  bad 
electrical  contact  was  at  one  time  regarded  simply  as  a  nuisance, 


BUBBLES  SET  AT  WORK  147 

because  of  the  singularly  uncertain  and  capricious  character  of  the 
current  transmitted  by  it.  Professor  Hughes  observed  its  sen- 
sitiveness to  sound-waves,  and  it  became  the  microphone,  which, 
duly  modified,  brought  the  telephone  from  the  whisper  of  a 
curious  toy  to  the  full  tones  which  ensured  commercial  success 
the  world  over.  This  same  "bad"  contact  turns  out  to  be  sensitive 
to  electric-  waves  also,  forming  indeed  nothing  else  than  the 
coherer  of  the  wireless  telegraph. 

Many  an  electrician  has  been  perplexed  and  thwarted  by  the 
small  bubbles  of  air  which  place  themselves  on  a  metallic  surface 
immersed  in  an  electric  bath,  interrupting  the  attack  sought  to 
be  carried  to  a  finish.  Happily  there  is  a  task  which  these  very 
bubbles  perform  as  if  they  had  been  created  for  no  other  purpose, 
namely,  the  re-sharpening  of  files.  First  the  dull  and  dirty  files 
are  placed  for  twelve  hours  in  a  fifteen  to  twenty  per  cent, 
solution  of  caustic  soda;  they  are  then  cleaned  with  a  scratch- 
brush  and  a  five  per  cent,  soda  solution.  Next  they  are  placed 
in  a  bath  of  six  parts  of  forty  per  cent,  nitric  acid,  three  parts 
sulphuric  acid,  and  100  parts  water,  each  file  being  connected 
to  a  plate  of  carbon  immersed  close  to  it,  by  means  of  a  copper 
plate  connecting  at  the  top  all  the  carbons  and  the  files.  This 
produces  a  short-circuited  battery  generating  gas  at  the  surface 
of  the  files ;  the  bubbles  which  adhere  to  the  points  of  the  files 
protect  them  from  being  eaten  away,  while  the  rest  of  the  metal 
is  being  etched.  Every  five  minutes  the  files  are  taken  out  and 
washed  in  water  to  remove  the  oxide  which  collects  on  their 
surfaces.  When  sufficiently  etched  they  are  placed  in  lime-water 
to  remove  any  adherent  acid,  dried  in  sawdust  to  prevent  rusting, 
and  rubbed  with  a  mixture  of  oil  and  turpentine.  Indispensable 
in  the  whole  process  is  the  protection  afforded  by  the  bubbles 
of  air. 

For  a  long  time  its  creation  of  sparks  kept  electrical  machinery 
out  of  mines  liable  to  fire-damp,  which  might  be  exploded  by 
these    sparks.      In    many    other    places    they 
worked  evils  quite  as  serious,  setting  fire  to      Evl1'  Be  Thou 
shavings,  cotton  and  such  like.     To-day  these 
very   sparks   are   applied   to  touching   off  the   charges   of   gas 
and  air  in  gas-engines  of  all  types,  whether  stationary,  or  for 


148  PROPERTIES 

automobiles  and  motor-boats.  In  another  respect  the  automobile 
should  be  provided  with  a  means  of  creating  what  is  usually 
considered  a  nuisance,  namely,  a  noise.  Moving-  rapidly  as  it 
does  on  thick  rubber  tires,  it  gives  no  warning  to  hapless  way- 
farers. In  Canadian  cities,  where  in  winter  deep  snow  may  muffle 
the  tread  of  horses,  every  sleigh,  under  severe  penalty,  must  be 
furnished  with  efficient  bells. 

Sometimes  an  important  property  has  unwelcome  effects  which, 

in  particular  cases,  cannot  be  applied  to  advantage,  and  must  be 

counterbalanced  with  as  much  care  as  possible. 

Compensating  Many  pieces  of  mechanism  from  the  qualities 
of  their  materials  are  subject  to  deviations 
which  must  be  compensated  by  introducing  equal  and  opposite 
action.  Tasks  of  this  kind  proceed  upon  an  intimate  acquaintance 
with  the  properties  of  substances  common  and  uncommon.  From 
the  first  making  of  clocks  there  was  much  trouble  due  to  changes 
of  temperature  which  affected  the  dimensions  of  pendulums,  and 
consequently  their  rate  of  going.  This  difficulty  is  overcome  by 
taking  advantage  of  the  fact  that  heat  expands  zinc  about  two- 
and-a-half  times  as  much  as  it  expands  steel.  Accordingly  the 
two-second  pendulum  of  the  great  clock  at  Westminster  is  built 
of  a  steel  rod  179  inches  in  length,  and  a  zinc  tube,  less  massive, 
126  inches  long;  they  are  joined  at  their  lower  ends  only  and 
are  parallel.  As  temperatures  vary,  the  fluctuations  in  length 
of  the  steel  compensate  those  which  occur  in  the  zinc.  Another 
mode  of  effecting  the  same  purpose  is  to  employ  a  cylinder  partly 
filled  with  mercury;  as  this  rises  when  warmed  it  exactly  com- 
pensates for  the  lengthening  by  expansion  of  its  supporting  rod 
of  steel. 

Gravity,  that  universal  force  at  which  we  have  just  glanced  as 
it  swings  a  pendulum,  cannot  be  banished,  but  its  downward 
push  may  be  balanced  by  an  equal  upward  thrust.  In  a  re- 
markable feat  Plateau  poured  oil  into  a  blend  of  water  and 
alcohol,  adding  alcohol  until  he  produced  a  mixture  having  the 
same  specific  gravity  as  the  oil — which  now  became  a  sphere, 
taking  its  place  in  the  middle  of  the  diluted  spirits.  He  then 
introduced  into  the  oil  a  vertical  disc  which  he  rotated;  very 
soon  spherules  of  oil  separated  themselves  from  the  parent  mass, 


GOOD  IN  EVERYTHING  149 

and  as  satellites  moved  in  the  same  direction  as  the  primary 
sphere,  because  immersed  as  they  were  in  the  diluted  alcohol, 
they  shared  the  direction  of  its  motion :  the  whole  afforded  a 
remarkable  illustration  of  how  nebulae  may  become  planets, 
moons,  and  suns. 

On  somewhat  the  same  principle  as  Plateau's  model  are  the 
liquid  compasses  for  ships.  Their  needles  are  disposed  within 
hollow  metallic  holders  of  the  same  specific  gravity  as  the  im- 
mersing liquid,  in  which  therefore  they  move  with  perfect  free- 
dom on  their  sapphire  bearings.  Sometimes  it  is  desired  to  use 
compass  needles  so  poised  that  they  will  respond  to  the  slightest 
magnetic  influence.  To  this  end  one  needle  is  placed  above 
another,  the  north  pole  of  the  first  over  the  south  pole  of  the 
second;  the  astatic  needle  formed  by  this  union  is  much  more 
sensitive  than  a  simple  needle.  The  astatic  needle,  for  all  its 
ingenuity,  is  little  used;  of  incomparably  more  importance  is 
that  other  magnetic  device,  the  telephone.  No  sooner  had  it  en- 
tered into  business  than  a  serious  fault  was  found  with  its  mes- 
sages; they  arrived  blurred  and  mingled  with  many  sounds  and 
noises,  as  if  the  conveying  wire  had  caught  every  audibility  of  a 
neighborhood.  The  difficulty  is  remedied  by  using  two  con- 
ductors instead  of  one,  and  so  arranging  them  that  the  currents 
induced  on  one  conductor  are  exactly  equal  and  opposite  to  those 
induced  in  the  other. 

If  properties  at  first  unwelcome  have  at  last  been  turned  to 
account,  so  also  have  properties  which  were  long  deemed  utterly 
useless.    A  big  and  interesting  book  might  be 
filled  with  the  story  of  how  by-products,  long     Properties  Long 
thrown  away  as  worthless,  have  rewarded  care-     Deemed  Useless 

are  Now 

ful  study  with  great  profit.   Thus  for  ages  was  Gainful 

bran  discarded  in  flour-mills :  to-day  it  may 
afford  all  the  miller's  profit,  or  even  more  than  that  profit.  In  the 
Southern  States  until  a  generation  ago  cotton  seed  was  regarded 
as  valueless.  At  present  that  product,  so  long  wasted,  is  the  basis 
of  a  great  industry,  a  ton  of  seed  yielding  about  1089  Ibs.  of 
meat  to  20  Ibs.  of  lint;  out  of  this  meat  800  Ibs.  are  cake  and 
meal;  the  remainder,  289  Ibs.,  forms  an  oil  which  furnishes  a 
substitute  for  olive  oil  and  lard.  Until  a  few  years  ago  glycerine 


150  PROPERTIES 

was  thrown  away  as  produced  in  candle-works  and  soap  factories. 
It  is  now  so  valuable  that  manufacturers  adopt  just  that  method 
of  preparing  fatty  acids  which  yields  most  glycerine  from  neutral 
fats.  So  in  paper-making,  the  soda  which  formerly  was  sent  into 
creeks  and  rivers  to  the  pollution  of  sources  of  water-supply,  is 
now  used  over  and  over  again,  largely  increasing  the  net  results 
of  manufacture.  No  industry  has  shown  of  late  years  so  large 
utilization  of  products  formerly  wasted  as  the  iron  and  steel 
manufacture.  Its  slags  are  made  into  bricks,  cement,  and  glassy 
non-conductors  of  heat  and  electricity.  Its  gases  are  used  for 
engines  developing  immense  motive  powers,  or  they  are  in  part 
condensed  for  valuable  acids  or  other  compounds.  In  these  cases 
and  thousands  more  the  question  has  been,  What  are  the  prop- 
erties of  these  by-products?  How  can  they  be  made  useful? 

Let    us    note    how    diverse    substances    are    separated    from 

one  another  by  taking  hold  of  differences  in  their  properties. 

When  a  handful  of  grain  which  has  just  passed 

Separation          under  a  flail  is  thrown  upward  in  a  breeze,  its 

Turns  on  chaff  ^  blown  much  farther  than  the  grain ; 

Diversity  of  ..... 

Properties.          tne  difference  in  breadth  of  surface,  joined  to 

a  difference  in  density,  enables  the  wind  to 
effect  a  thorough  separation.  A  common  fanning  mill,  with  its 
quick  air  current,  works  much  better  than  the  fitful  wind,  because 
continuously.  That  simple  machine,  like  every  other  which  takes 
a  mixture  and  separates  its  ingredients,  seizes  upon  a  difference 
in  properties.  In  Edison's  apparatus  for  removing  iron  from 
sand  or  dust,  a  series  of  powerful  magnets  overhang  a  stream 
of  sand  or  powdered  material,  deflecting  the  iron  particles  so  that 
they  fall  into  a  bin  by  themselves,  while  the  trash  goes  into  an 
adjoining  larger  bin.  The  Hungarian  process  of  flour-milling 
first  crushes  wheat  through  rollers ;  the  various  products  are  then 
separated  by  processes  which  lay  hold  of  differences  in  specific 
gravity — often  but  slight. 

A  feat  more  difficult  than  that  of  the  Hungarian  mill  would 
seem  to  be  the  division  of  diamonds  from  other  stones.  It  has 
been  accomplished  by  Mr.  Frederick  Kersten  of  Kimberley,  South 
Africa.  He  noticed  one  day  at  his  elbow  a  rough  diamond  and 
a  garnet  on  a  board.  He  raised  one  end  of  this  board,  and  while 


VARIETIES  OF  IRON  151 

the  garnet  slipped  off,  the  diamond  remained  undisturbed.  What 
was  the  reason?  He  observed  that  the  wood  bore  a  coating  of 
grease,  which  possibly  had  held  the  diamond  while  the  garnet 
had  slipped  away.  He  took  a  wider  board,  greased  it,  and  dropped 
upon  it  a  handful  of  small  stones,  some  of  which  were  rough 
diamonds.  He  found  that  by  inclining  the  board  a  little,  and 
vibrating  it  carefully,  all  the  stones  but  the  diamonds  fell  off, 
while  the  diamonds  stuck  to  the  grease.  He  forthwith  built  a 
machine  with  a  greasy  board  as  its  separator,  and  scored  a 
success. 

On  quite  a  different  plan  is  built  the  coal  washer  which  sepa- 
rates coal  from  slate.  Pulses  of  water  are  sent  upward  through 
a  sieve  so  as  to  strike  a  broken  mixture  of  coal  and  slate,  making 
a  quicksand  of  the  mass.  Because  the  slate  is  heavier  than  the 
coal  it  is  not  carried  so  far,  and  is  therefore  caught  in  a  separate 
stream  and  thrown  away. 

Separations,  such  as  we  just  considered,  turn  upon  obvious 
differences  in  density.    Properties  not  obvious,  yet  highly  useful, 
come  into  view  year  by  year  as  observers  grow 
more  alert  and  keen,  as  new  instruments  are   Properties  Newly 
devised  for  their  aid,  as  measurements  become      Discovered  and 
more  refined,  so  that  matter  is  constantly  found          Produced, 
to  be  vastly  richer  in  properties  than  was  for- 
merly supposed.     We  have  long  known  that  carbon  has  forms 
which  vary  as  widely  as  coal,  graphite  and  the  diamond.     Many 
other  elements  are  detected  in  a  similar  masquerade.     Iron,  for 
instance,  takes  three  forms,  alpha,  beta,  and  gamma.    Alpha  iron 
is  soft,  weak,  ductile  and  strongly  magnetic;  beta  iron  is  hard, 
brittle  and  feebly  magnetic ;  gamma  iron  is  also  hard  and  feebly 
magnetic,  yet  ductile.     Joule,  the  famous  English  experimenter, 
prepared  an  amalgam  of  iron  with  mercury;  when  he  distilled 
away  the  mercury,  'the  remaining  iron  took  fire  on  exposure  to 
the  air,  proving  itself  to  be  different  from  ordinary  iron.    Mois- 
san  has  shown  that  similar  effects  follow  when  chromium,  manga- 
nese, cobalt  and  nickel  are  released   from  amalgamation   with 
mercury. 

At  first  steel  was  valued  for  its  strength  and  elasticity ;  to-day 
we  also  inquire  as  to  its  conductivity  for  heat  or  electricity,  its 


152  PROPERTIES 


behavior  in  powerful  magnetic  fields,  its  capacity  to  absorb  or 
reflect  rays  luminous  or  other.  As  art  moves  onward  we  enter 
upon  new  powers  to  change  the  properties  of  matter,  compassing 
new  intensities  of  heat  and  cold,  each  with  new  effects  upon 
tenacity,  elasticity,  conductivity.  So  also  with  the  extreme  pres- 
sures, possible  only  with  modern  hydraulic  apparatus,  which 
prove  marble  to  be  plastic,  and  reduce  wood  to  a  density  compar- 
able with  that  of  coal,  explaining  how  anthracite  has  been  con- 
solidated from  the  vegetation  of  long  ago. 

And  one  discovery  but  breaks  the  path  for  another,  and  so  on 
indefinitely.  Coming  upon  a  new  property,  the  sensitiveness  of 
silver  compounds  to  light,  meant  a  new  means  of  further  dis- 
covery, the  photographic  plate.  That  plate,  responsive  to  rays 
which  fall  without  response  upon  the  retina,  reveals  much  to  us 
otherwise  unknown  and  unsuspected.  Of  old  when  an  observer 
saw  nothing,  he  thought  there  was  nothing  to  see.  We  know 
better  now.  Thanks  to  the  sensitive  plate  we  have  reason  to 
believe  that  properties,  once  deemed  exceptional,  are  really  uni- 
versal. Phosphorescence,  for  ages  familiar  in  the  firefly,  in 
decaying  logs  and  fish,  now  declares  itself  excitable  in  all  sub- 
stances whatever,  although  usually  in  but  slight  measure.  The 
case  is  typical :  the  polariscope,  the  spectroscope,  the  fluoroscope, 
the  magnetometer,  the  electroscope,  each  employing  as  its  core 
a  substance  of  extraordinary  susceptibility,  detects  that  quality 
in  everything  brought  within  its  play.  Thus  from  day  to  day 
matter  is  disclosed  in  new  wealths  of  properties,  and  therefore 
in  new  and  corresponding  complexities  of  structure.  In  ages 
past  mankind  was  on  nodding  terms  with  many  things,  and  had 
no  intimate  knowledge  of  anything. 

With  materials  before  him  richer  in  array  than  ever  before, 
and  better  understood  than  of  old,  the  inventor  asks,  What 
properties  do  I  wish  in  a  particular  substance?  Then,  he  pro- 
ceeds to  make,  if  he  can,  a  dye  of  unfading  permanence,  an 
insulator  resistant  to  high  temperatures,  an  alloy  which  when 
subjected  to  heat  or  cold  remains  unaltered  in  dimensions.  He 
finds  materials  much  more  under  command  than  a  century  ago 
could  have  been  imagined,  as  the  glass  manufacture,  the  alloying 
industry,  the  making  of  artificial  dyes,  abundantly  prove. 


EDISON'S  STORE-HOUSE  153 

Mr.  Edison,  for  aid  in  finding  just  the  substance  he  needs  for 
a  new  purpose,  has  at  his  laboratory  in  Orange,  New  Jersey,  a 
large  store-room   filled   with   materials  of  all 
kinds.    He  may  wish  a  particularly  high  degree     Edison's  Ware- 
of  elasticity,  hardness,  abrasive  power,  or  what     house  as  an  Aid. 
not;  to  provide  these  he  has  gathered  a  wide 
diversity  of  woods,  ivories,  fibres,  horn,  glass,  porcelain,  metals 
pure  and  alloyed,  alkalis,  acids,  oils,  varnishes  and  so  on.     Take 
one  example  from  among  many  which  might  be'  given  from  his 
shelves ;  he  finds  that  a  sapphire  furnishes  the  best  stylus  where- 
with to  cut  a  channel  on  a  phonographic  cylinder.     Hard,  flinty 
particles  from  the  air  are  apt  to  enter  the  wax,  so  as  to  blunt  a 
cutting  edge.     Diamonds  would  be  best  as  channelers,  but  their 
cost  obliges  him  to  choose  sapphires  as  next  best ;  they  are  pur- 
chasable at  reasonable  prices  and  last  ten  years  under  ordinary 
conditions  of  wear. 


CHAPTER  XII 
PROPERTIES— Continued 

Producing  more  and  better  light  from  both  gas  and  electricity  .  .  .  The 
Drummond  light  .  .  .  The  Welsbach  mantle  .  .  .  Many  rivals  of  carbon 
filaments  and  pencils  .  .  .  Flaming  arcs  and  tubes  of  mercury  vapor. 

MR.  EDISON  has  achieved  triumphs  not  only  in  giving  sound 
its  lasting  registration,  but  in  producing  an  electric  light  of 
new  economy.     Both  exploits  proceeded  upon  a  masterly  knowl- 
edge of  properties.    A  century  ago  candles  provided  illumination 
both  to  rich  and  poor,  the  sole  difference  being 

that  wax  sh°ne  in  the  Palace  and  tallow  in  the 
hut.  The  oil  lamps  which  gleamed  in  the  light- 
houses of  England  and  America,  for  all  their  bigness,  were  plainly 
of  kin  to  the  Eskimo  saucer  filled  with  blubber,  edged  with  moss 
as  wick.  Yet  for  ages,  from  every  hearth  in  Christendom,  there 
had  been  the  promise  of  better  things  as  bituminous  coals,  or 
sticks  of  wood,  had  cheered  as  much  by  their  light  as  by  their 
warmth.  We  owe  much  to  James  Watt,  who  improved  the  steam- 
engine  and  gave  it  essentially  the  form  it  retains  to  the  present 
hour.  We  owe  also  a  weighty  debt  to  an  assistant  of  his,  Wil- 
liam Murdock,  who,  thanks  to  a  suggestion  from  Lord  Dun- 
donald,  attentively  observed  the  process  by  which  coals  produce 
light.  He  saw  that  under  stress  of  intense  heat  the  solid  fuel 
emitted  streams  of  gas  which  burned  with  great  brilliancy.  Here 
gas-making  and  gas-burning  went  on  at  the  same  moment  in  the 
same  place;  might  the  process  be  separated,  so  that  gas  might 
be  made  here,  and  burned  elsewhere  at  any  convenient  time  ?  An 
experiment  proved  the  project  to  be  feasible,  and  forthwith  the 
Soho  Works,  near  Birmingham,  in  which  Watt's  engines  were 
built,  were  lighted  by  gas.  Such  was  the  beginning  of  an  industry 
now  important  in  many  ways.  To-day  gas  not  only  yields  light, 


WELSBACH  MANTLE  155 

but  heat  and  power,  while,  especially  in  metallurgy,  fuels  are  more 
and  more  used  after  reduction  to  the  gaseous  form. 

Early  in  the  day  of  gas-making  it  was  noticed  that  gases  of 
various  kinds  differed  much  in  light-giving  quality.  It  was 
presently  shown  that  their  light  depended  on 

the  carbon  brought  to  incandescence  in  a  flame  ;        How  the  Gas 
r    ,  ,  .  .   ,  Mantle  was 

in  the  absence  of  that  carbon,  as  when  a  jet  of  invented. 

pure  hydrogen  was  consumed,  extreme  heat 
was  accompanied  by  no  light  whatever.  Then  came  a  capital  dis- 
covery, namely,  that  lime  introduced  within  a  burning  jet  of 
hydrogen  became  intensely  luminous  while  itself  but  slowly  con- 
sumed. Adopting  lime  for  the  core  of  his  apparatus,  Captain 
Thomas  Drummond,  of  the  Royal  Engineers,  in  1835  devised  the 
lime  light.  Upon  a  block  of  pure,  compressed  quick  lime,  he 
directed  a  jet  of  burning  gas,  obtaining  a  beam  of  great  vividness 
still  employed  in  stereopticons  and  in  theatres.  For  modern  types 
of  the  Drummond  lamp  a  twin  jet  of  hydrogen  and  oxygen  is 
used.  Lime  has  many  sister  substances  having  light-giving  qual- 
ity when  highly  heated,  and  among  them  are  many  rare  earths, 
oxides  of  uncommon  elements.  These  strange  substances  were 
destined  to  play  a  prominent  part  in  the  battle  between  gas  and 
electricity  as  illuminants.  When  Edison  in  1878  perfected  his 
incandescent  bulb,  it  seemed  as  if  electricity  were  soon  to  be  the 
sole  illuminator  of  houses.  But  the  gas  engineers  were  to  be 
rejoiced  by  the  invention  of  a  mantle  which  quadrupled  the  bril- 
lancy  of  a  gas  flame,  withstanding  the  rivalry  of  electricity  in  a 
notable  degree.  This  mantle  was  invented  by  Dr.  Auer  von 
Welsbach,  a  chemist  of  Vienna,  who  virtually  adopted  the  prin- 
ciple of  the  Drummond  light.  His  efforts  give  us  an  admirable 
example  of  an  inventor  passing  from  a  hint  to  a  test,  day  after 
day  meeting  new  difficulties  with  unfailing  courage  and  resource- 
fulness. 

In  1880  Dr.  von  Welsbach  took  up  the  study  of  rare  earths, 
mainly  with  a  view  to  ascertaining  their  value  as  illuminants.  As 
he  brought  one  specimen  after  another  to  melting  heat  on  bits  of 
platinum  wire,  he  found  that  the  little  beads  formed  were  un- 
favorable in  shape  to  the  production  of  light.  Then  came  into 
his  mind  an  idea  of  that  golden  quality  which  occurs  only  to  the 


156  PROPERTIES 

man  who  earns  it :  Why  not  soak  cotton  with  solutions  of  salts  of 
rare  earths,  burn  the  cotton  and  leave  behind  an  earthy  skeleton 
of  slight  thickness  and  much  surface?  Experiment  proved  that 
the  idea  had  promise,  but  the  skeletons  crumbled  to  dust  with 
the  least  tremor.  For  success  a  fair  degree  of  cohesion  was  im- 
perative, but  to  secure  that  cohesion  demanded  skill,  resource,  and 
patience.  After. a  long  series  of  trials  a  mantle  was  made  with 
lanthanum  oxide;  immersed  in  flame  its  beam  was  particularly 
bright,  now  for  the  first  time  suggesting  that  the  rare  earths 
might  yield  light  on  a  large  scale.  But  trouble  was  at  hand,  to 
be  overcome  only  at  the  end  of  much  toil. 

During  an  absence  of  several  days,  the  inventor  left  a  mantle 
of  lanthanum  oxide  locked  up  in  his  laboratory.  When  he  re- 
turned it  had  fallen  to  powder,  having  attracted  from  the  atmo- 
sphere both  moisture  and  carbon  dioxide.  Evidently  this  harm- 
ful attraction  must  be  avoided  by  adding  an  ingredient  to  keep 
the  mantle  dry  and  preserve  it  from  union  with  carbon  dioxide. 
For  this  purpose  magnesia  was  chosen;  the  resulting  compound 
proved  to  be  durable,  and  gave  an  agreeable  light  of  moderate  in- 
tensity. But,  alas,  after  glowing  about  seventy  hours,  the  mantle 
failed  in  its  radiance,  becoming  of  glassy  and  translucent  texture. 
Thus  impeded,  the  untiring  inventor  turned  to  mixtures  having 
zirconium  as  a  basis ;  these  not  only  gave  a  steady  beam,  but  ex- 
tended to  hundreds  of  hours  the  life  of  a  mantle.  Still  bent  on 
getting  more  light  if  he  could,  Dr.  von  Welsbach  tested  thorium 
oxide  with  gratifying  results;  yet,  strange  to  say,  when  he  had 
purified  this  material  to  the  utmost,  his  light  fell  off  in  an  unac- 
countable fashion.  What  could  be  the  matter?  Surely  in  the 
purifying  process  some  invaluable  element  had  been  cast  aside. 
This  element,  in  the  researches  of  an  associate,  Mr.  Ludwig  Hai- 
tinger,  proved  to  be  cerium  in  minute  quantity.  Here  was  a  dis- 
covery of  the  highest  moment;  at  the  end  of  many  experiments 
it  was  determined  that  one  per  cent,  of  cerium  and  ninety-nine  per 
cent,  of  thorium  oxide  are  the  best  proportions  for  a  mantle  such 
as  we  use  to-day.  Why  these  proportions  are  best  nobody  knows, 
any  more  than  why  one  per  cent,  of  carbon  added  to  iron  gives  us 
a  steel  incomparably  better  than  iron  for  many  uses.  A  Welsbach 
mantle  has  good  points  apart  from  its  economy  of  gas.  Its  com- 


DR.  CARL  FREIHERR  AUER  VON  WELSBACH 
OF  VIENNA. 


ALCOHOL  LAMP 


157 


bustion  is  thorough,  so  that  it  throws  into  the  air  a  much  lower 
percentage  of  injurious  products  than  does  an  ordinary  gas  flame. 
It  never  smokes,  and  its  light  is  so  steady  as  to  be  available  for 
work  with  the  microscope  and  other  exacting  demands.  It  has 
one  defect  which  may  yet  be  removed :  its  light 
has  a  somewhat  unpleasant  tinge  of  green.  In 
another  chapter  of  this  book,  producer  gas,  much 
cheaper  than  common  illuminating  gas,  is  de- 
scribed. Dowson  producer  gas,  with  a  Welsbach 
mantle,  yields  a  light  of  8  to  10  candle-power 
with  a  consumption  of  4.5  to  4.8  cubic  feet  per 
hour. 

Thus  far  no  successful  mantle  for  a  petroleum 
lamp  has  been  devised.  With  alcohol  a  mantle 
yields  a  brilliant  flame.  A  lamp  with  a  Boivin 
burner  and  a  Welsbach  mantle  has  given  a  light 
of  30.35  candle-power  for  57  hours  and  5  minutes 
in  consuming  one  gallon  of  alcohol,  almost  twice 
as  much  light  as  given  by  a  Miller  lamp  with  a 
round  wick  and  a  central  draft,  burning  a  gallon 
of  kerosene.  In  the  United  States  on  January  i, 
1907,  there  will  cease  to  be  an  excise  tax  on 
alcohol  used  in  the  arts,  a  denaturalizing  process 
rendering  the  liquid  unfit  to  drink.  As  this 
alcohol  may  be  easily  produced  from  grain  or 
potatoes  at  20  to  25  cents  a  gallon,  a  capital 
illuminant  will  be  available  for  the  public,  as  well 
as  an  excellent  fuel  and  a  substitute  for  gas  or 
gasoline  in  motors. 

As  first  manufactured,  gas-mantles  were 
woven,  they  are  now  knitted,— a  change  for  the  better  in  close- 
ness and  firmness  of  texture.  Nearly  all  the  thorium  used  for 
mantles  is  found  in  the  monazite  sands  of  the  provinces  of  Bahia 
and  Espirito  Santo,  along  the  coast  of  Brazil.  These  sands  were 
for  a  long  time  valuable  only  for  the  zinc  they  contained.  To- 
day the  thorium  they  carry  is  of  vastly  more  account ;  for  chemical 
treatment  this  is  sent  to  Germany  whence  the  manufactured 
product  is  borne  to  every  quarter  of  the  globe. 


Boivin  burner 

for  alcohol, 

attachable 

to  any 

lamp 


158 


PROPERTIES 


Improvements 
in  Electric  Light- 
ing:  Incandescent 
Lamps. 


While  the  Welsbach-  mantles  have  been  constantly  improved 
in  quality,  and  given  new  and  inverted  forms  of  special  value, 
the  inventors  in  the  field  of  electric  lighting 
have  not  stood  still.  For  interior  illumination 
the  Edison  incandescent  bulb  still  holds  its  own 
despite  many  a  threat  of  dispossession.  Since 
1 88 1  its  details  of  manufacture  have  been 
steadily  bettered  and  its  price  much  reduced,  while  its  consump- 
tion of  current  has  fallen  from  5.8  watts  per  candle  to  3.1.  This 

advance,  marked  as  it  is,  leaves  a 
long  path  ahead  of  the  inventor 
whose  estimate  is  that  were  the 
whole  of  an  electric  current  trans- 
formed into  light,  a  candle  would 
cost  us  but  .11  of  a  watt,  that  is,  but 
one  twenty-eighth  part  as  much  as 
when  we  set  a  carbon  filament  aglow. 
In  electrical  terms  a  horse-power 
yields  748  watts,  representing,  were 
there  no  waste  in  conversion,  no  less 
than  425  lamps  each  of  16  candle- 
power. 

It  is  this  immense  margin  for  im- 
provement that  has  spurred  in- 
genuity to  attack  the  problem  of 
electric  lighting  from  many  new 
sides.  The  Genera1  Electric  Com- 
pany produces  a  carbon  filament  of 
one  fifth  greater  efficiency  than  an 
ordinary  untreated  filament.  Fibers 
of  the  usual  cellulose  kind  are  en- 
closed in  a  carbon  box,  placed  in  a  carbon-tube  resistance  furnace 
heated  to  between  3,000°  and  3,700°  C.  This  converts  the  filament 
into  a  graphite  of  increased  luminosity  which,  furthermore, 
blackens  its  enclosing  glass  much  less  than  a  common  filament 
does. 

In  the  early  days  of  electric  lighting  a  good  many  experiments 
were  tried  with  threads  of  platinum,  but  without  success.    Tha; 


Alcohol  lamp  with 
ventilating  hood. 


NEW  ELECTRIC  LAMPS 


159 


metal  remains  unmelted  at  a  very  high  temperature,  but  as  a 
light-giver  its  quality  is  poor.     Of  late  years  investigators  have 


ii    m  m      ;: 


. 

p 

'  '  ' 


Welsbach  mantle. 


turned  to  other  metals,  of  high  melting  points,  and  with  results 
so  remarkable  that  we  may  expect  some  of  them  to  be  in  general 
use  in  the  near  future.  Tantalum,  a  rare  and  costly  metal,  has 
been  found  to  give  a  candle-power  with  as  little  as  two  watts  and, 
in  specially  favorable  circumstances,  with  only  1.85  watts. 


160 


PROPERTIES 


Tantalum  lamp. 


Osmium,  in  the  hands  of  Dr.  Auer  von  Welsbach,  reduces  this 
figure  to  1.5  watts.    Dr.  Hans  Kuzel,  of  Baden,  Austria,  has  em- 
ployed filaments  of  tungsten  in  lamps  which 
he  claims  demanded  only  one  watt  per  candle. 
From    among    these    new    lamps    it    seems 
highly  probable  that  as  soon  as  methods  of 
manufacture    are    settled    and    standardized 
the  world  will  be  given  an  electric  light,  in 
small  units,  much  cheaper  than  ever  before. 
For    large    spaces   indoors    and    for    out 
of   doors   the   arc-lamp  maintains   its   popu- 
larity  in   much   the    form 
originally        devised        by     New  Arc  Lamps. 
Mr.  Charles  F.  Brush  of 
Cleveland.     But,  as  in  the  case  of  the  in- 
candescent bulb,   many  a   rival  is  now   dis- 
puting the  field,  so  that  supersedure  may  be 
close  at  hand.     In  what  are  known  as  flaming  or  luminous  arcs 
the  carbon  pencils  are  impregnated  with  salts  of  the  calcium 
group  of  elements,  of  extreme  luminosity. 
In  these  lamps  the  electric  arc  itself  is  the 
chief    source    of    light,    instead    of    the 
glowing    end    of    the    positive    carbon    as 
in  a  common  arc  lamp.     As  the  calcium 
.salts    volatilize    into    gases    they    provide 
a  path  of  less  resistance  than  air  for  the 
passage  of  the  current,   so  that  the  elec- 
trodes may  be  drawn  apart  to  a  distance 
which  may  be  as  much  as  2^  inches.  These 
lamps  require  free  ventilation,  so  that  they 
must  be  open.     Their  economy  is  extraor- 
dinary, a  candle-power  being  afforded  for 
•353  watt,  as  against  1.78  watts  for  an  en- 
closed  arc   lamp,    a   five-fold   gain   in    ef- 
fectiveness.    To  renew  the  carbons,  which 
waste    rapidly,     a    new     device     provides 
fresh    pencils,    cartridge    fashion,    as    re-        Tungsten  lamp  of 
quired.   Without  this  aid,  trimming  is  often         Dr.  Hans  Kuzel. 


HEWITT  LAMP  161 

necessary,  and  this  fact  joined  to  the  high  cost  of  the  carbons 
lessens  the  net  gain  in  their  use.  On  another  line  of  experiment 
noteworthy  results  have  been  reached  with  metallic  oxides. 
Magnetite,  an  oxide  of  iron,  has  developed  a  candle-power  with 
but  one  half  of  one  watt.  Ferro-titanium,  a  compound  of  iron 
and  titanium,  has  given  a  candle-power  with  only  one  third  of  a 


Hewitt  mercury-vapor  lamp. 

watt,  and  it  is  expected  that  still  higher  efficiencies  will  soon  be 
attained  with  this  wonderful  compound. 

From  quite  another  side  Mr.  Peter  Cooper  Hewitt  enters  the 
field  of  light  production,  utilizing  the  glow  of  a  vapor  instead  of 
a  solid  stick.  His  lamp  is  a  long,  slender  tube  of  glass;  within 
each  end  is  sealed  a  metallic  wire ;  at  one  end  is  a  little  mercury. 
When  a  powerful  pump  has  exhausted  the  tube  to  a  high  degree 
it  is  sealed,  and  its  wire  terminals  are  placed 

in  an  electric  circuit.     On  tilting  the  tube  the     Hewitt  Mercury- 

n  .  .  Vapor  Lamp, 

mercury   flows    from   end   to   end,    an   arc   is 

formed,  and  the  mercury  vapor  becomes  luminous.     This  vapor 
remains  unconsumed,  and  the  lamp  asks  no  attention  whatever. 


162  PROPERTIES 

Its  rays  are  greenish,  so  that  where  normal  colors  are  desired,  it 
is  well  to  use  supplementary  lamps  of  carbon  filaments  to  furnish 
red  rays.  For  streets,  squares,  freight-sheds  and  the  like,  the 
Hewitt  light  is  capital  just  as  produced,  its  rays  being  widely 
diffused  and  casting  no  heavy  shadows.  Its  high  actinic  power 
makes  it  specially  useful  to  photographers,  while  in  factories, 
drafting  rooms,  composing  rooms  and  so  on,  its  color  is  unob- 
jectionable. Its  cost  is  small,  as  a  candle-power  is  produced  in 
large  tubes  with  but  0.55  of  a  watt.  A  Hewitt  lamp  of  automatic 
type,  recently  devised,  has  a  small  solenoid  or  magnet  on  the  sus- 
pension bar  just  above  the  holder.  On  closing  the  circuit  the  cur- 
rent flows  through  this  solenoid  which  instantly  tilts  the  tube  and 
starts  the  light.  This  lamp  is  particularly  suited  to  places,  such 
as  the  lofty  ceilings  of  foundries,  where  it  would  be  difficult  to 
tilt  the  tube  by  hand.  Hewitt  lamps  use  either  a  direct  or  an 
alternating  current. 

In  an  earlier  chapter  we  glanced  at  reflectors  and  refractors, 
newly  invented,  which  give  light  its  most  useful  paths  with  as 
little  avoidable  loss  as  possible.  These  devices,  applied  to  Wels- 
bach  burners  and  the  new  electric  lamps,  greatly  economize 
modern  illumination  in  comparison  with  that  of  former  times. 

1  In  February,  1906,  the  Illuminating  Engineering  Society  was  established 
in  New  York.  Its  secretary  is  A.  H.  Elliott,  4  Irving  Place,  New  York. 
The  Society  publishes  its  proceedings  and  discussions. 


CHAPTER  XIII 
/ 

PROPERTlES-Continued.    STEEL 

Its  new  varieties  are  virtually  new  metals,  strong,  tough,  and  heat  re- 
sisting in  degrees  priceless  to  the  arts  .  .  .  Minute  admixtures  in  other 
alloys  are  most  potent. 

FROM  a  brief  consideration  of  illuminants  let  us  pass  to  a 
rapid  survey  of  a  most  important  group  of  structural  mate- 
rials, the  steels.  Here,  as  always,  we  shall  find  how  abundant  are 
the  harvests  reaped  in  a  searching  study  of  properties.  Within 
the  past  fifty  years  new  steels  have  been  produced  in  so  ample 
and  rich  a  variety  that  we  have  gained  what  are  virtually  many 
new  metals  of  inestimable  qualities. 

In   1781   Professor  Torbern   Bergman,  of  the  University  of 
Upsala,  in  Sweden,  showed  that  steel  mainly  differs  from  iron 
in  containing  about  one  fifth  of  one  per  cent,  of  plumbago,  or  car- 
bon, as  we  would  say  now.    Steels  may  contain  all  the  way  from 
one  tenth  to  one  and  a  half  per  cent,  of  carbon ; 

the  lower  this  percentage,  the  more  nearly  does 
Strength. 

the  steel  approach  wrought  iron  in  softness; 

as  the  proportion  of  "carbon  increases  up  to  one  per  cent,  the 
steel  increases  in  tenacity,  beyond  one  per  cent,  tenacity  dimin- 
ishes and  brittleness  is  augmented.  Hardness  depends  upon  the 
percentage  of  carbon  a  steel  contains.  Physical  conditions  are 
almost  as  important  as  chemical  composition;  a  mass  of  red-hot 
steel,  carefully  hammered  or  pressed  is  thereby  strengthened,  an 
effect  due  either  to  minimizing  the  process  of  crystallization,  or  to 
breaking  up  crystals  as  fast  as  they  form.  The  microscope  re- 
veals many  details  of  structure  in  steel,  and  has  enabled  the 
analysts  greatly  to  economize  the  manufacture  of  desired 
varieties.  Under  the  microscope  steels  much  resemble  crystalline 
rocks  in  structure,  with  constituents  differing  widely.  Of  these 

163 


164  PROPERTIES— STEEL 

the  most  important  is  ferrite,  a  pure  or  nearly  pure  metallic  iron, 
soft,  weak,  ductile,  of  high  electric  conductivity.  Next  in  im- 
portance is  cementite,  an  iron  carbide  (Fe3C),  harder  than  glass 
and  nearly  as  brittle,  but  probably  very  strong  under  gradually 
and  axially  applied  stress.  A  third  constituent,  austenite,  is  a 
solid  solution  of  carbon,  or  perhaps  of  an  iron  carbide,  in  gamma 
allotropic  iron  (there  being  also  alpha  and  beta  irons).  Austen- 
ite is  hard  and  brittle  when  cold,  is  stable  at  high  temperatures, 
and  is  slowly  transformed  by  reaction  into  compounds  of  ferrite 
or  cementite.  Several  other  ingredients  of  importance,  as  pearlite, 
illustrated  on  the  opposite  page,  have  also  been  studied.1 

While  carbon  is  the  most  decisive  element  in  admixture,  other 
ingredients  have  marked  influence,  silicon  and  manganese  espe- 
cially. The  process  invented  by  Bessemer,  described  by  himself 
in  another  chapter  of  this  book,  as  introduced  in  1855,  revolution- 
ized the  steel  manufacture  by  its  directness,  cheapness  and  speed. 
It  consists  in  burning  out  from  pig-iron,  by  a  hot  air  blast,  all 
or  nearly  all  its  carbon.  Then  spiegeleisen,  or  other  mixture, 
containing  a  definite  quantity  of  carbon  and  manganese,  is  added 
to  the  molten  mass,  yielding  steel  of  the  quality  desired.  This 
method  produces  more  rails  for  railroads  than  any  competing 
method ;  in  other  fields  it  is  being  rivalled  more  and  more  severely 
by  the  open  hearth  process. 

Steel  making  by  the  open  hearth  process  is  chiefly  due  to  the 

late  Sir  William  Siemens.    In  a  gas  producer  he  gave  his  fuel 

the  gaseous  form,  in  which  it  is  more  easily 

T  Th®  °pen  controlled  and  more  efficient  than  when  solid. 

Hearth  Process.        -  . 

Of   more   importance   were   his   regenerators, 

chambers  of  brickwork,  heated  by  the  products  of  combustion,  and 
then  employed  to  warm  incoming  currents  of  air  and  gas  on  their 
way  to  the  furnace.  The  Siemens  furnace  has  been  modified  in 
many  ways  and  much  improved  in  its  details.  A  good  example 
of  an  open  hearth  furnace,  as  planned  by  the  late  Mr.  Bernard 
Dawson,  is  shown  on  page  165.  It  centers  in  a  large  hearth  built 
of  refractory  materials,  upon  which  the  metal  is  melted  as  flames 
play  over  it.  At  each  end  are  two  regenerators  filled  with  checker 

1  Henry  Marion  Howe,  "Iron,  Steel  and  Other  Alloys."  Second  edition. 
Published  by  Albert  Sauveur,  Cambridge,  Mass.,  1906. 


Pearlite,    magnified    about 
750    diameters. 


Steel    containing    more    than    nine- 
tenths  of  one  per  cent  of  crystals 
of  pearlite,  surrounded  by  en- 
velopes     of      cementite 
(Fe3C).     Magnified 
200  diameters. 


CLEANING  CARS  BY  THE  "VACUUM"  METHOD. 


OPEN  HEARTH  PROCESS 


165 


firebricks  through  which  air  or  gas  passes  on  its  way  to  the  fur- 
nace, and  through  which,  at  due  intervals,  the  products  of  com- 
bustion emerge  as  they  pass  to  the  stack.  On  each  side,  one  of 
the  regenerators  is  for  air,  the  other  for  gas ;  between  them  is 


Open  hearth  furnace. 

a  substantial  wall  to  prevent  any  mixing  before  their  currents 
reach  the  hearth.  It  is  in  the  regenerator,  which  utilizes  heat  which 
otherwise  would  be  wasted,  that  the  open  hearth  displays  its  best 
feature.  Its  products  vary  in  composition  as  its  raw  materials 
vary,  whether  pig-iron  of  a  specific  kind,  a  particular  ore,  or 
scrap;  and  just  as  in  the  Bessemer  process,  a  harmful  element,  as 
phosphorus,  is  removed  almost  wholly  by  the  addition  of  a  suit- 
able ingredient,  such  as  lime.  In  excellence  and  uniformity  of 
quality  open  hearth  steels  are  preferred  to  those  of  the  Bessemer 
converter,  even  for  railroad  rails  which  for  years  were  made 
solely  by  the  Bessemer  process. 

A  remarkable  improvement  in  blast-furnace  practice,  cheapen- 
ing cast  or  pig-iron,  and  therefore  lowering  the  cost  of  derived 
steels,  is  the  dry-blast  process  due  to  Mr.  James 
Gayley,  of  Pittsburg.    It  has  long  been  known 
that  blast-furnaces  ask  more  fuel  in  warm  and 
damp  weather  than  in  cold  and  dry  weather; 
beginning  with  this  familiar  fact  Mr.  Gayley  proceeded  to  dry  the 
air  blown  into  his  furnaces,  by  passing  it  around  large  coils  of 


The 
Dry-Blast 
Process. 


166  PROPERTIES— STEEL 

iron  pipes  throrgh  which  a  freezing  mixture  circulated,  melting 
the  snow  as  formed  by  passing  hot  brine  through  the  pipes,  a  few 
of  them  at  a  time.  The  air  thus  dried  was  then  heated  by  being 
sent  through  hot  blast  stoves  in  the  usual  mode.  This  simple 
drying  of  the  blast  saves  about  19  per  cent,  of  the  fuel,  and  makes 
the  action  of  the  furnace  much  more  regular  than  when  ordinary 
air  is  used.  It  lowers  the  temperature  of  the  gases  which  escape 
from  the  top  of  the  furnace,  and  raises  their  percentage  of  carbon 
dioxide,  symptoms  of  the  great  increase  in  fuel  efficiency.  Atmo- 
spheric moisture  has  a  cooling  effect  on  the  lower  part  of  a  fur- 
nace, just  where  the  highest  temperature  is  needed  to  melt  the 
iron  and  slag,  remove  the  sulphur  and  deoxidize  the  silica.  A 
comparatively  small  increase  of  temperature  by  broadening  the 
margin  of  effective  heat,  which  margin  at  best  is  narrow,  has  the 
astonishing  effect  of  economizing  fuel  to  the  extent  stated,  19 
per  cent.1 

What  is  chiefly  sought  in  steel  is  tensile  strength,  next  in  value 
is  elasticity ;  in  some  cases  hardness  is  indispensable.  By  varying 
the  proportions  of  the  carbon,  silicon  and  man- 
Steels  to  Order.  ganese  added  to  his  iron,  the  steel-maker  pro- 
duces an  alloy  with  the  tenacity,  elasticity  or 
hardness  he  wishes.  Nickel,  as  a  further  ingredient,  in  certain 
proportions  yields  an  astonishing  gain.  A  steel  containing  fifteen 
pei  cent,  of  nickel  has  shown  a  tensile  strength  of  244,000  pounds 
to  the  square  inch,  four  times  as  much  as  before  admixture ;  the 
elastic  limit  also  was  much  increased.  Hardness  and  strength 
tend  to  exclude  ductility,  but  nickel  steel  is  at  once  strong,  hard 
and  extremely  ductile ;  hence  its  use  for  armor  plate,  great  guns, 
and  the  barrels  of  small  arms.  Nothing  but  the  high  price  of  nickel 
prevents  these  alloys  from  having  wide  utilization,  for  they  mean 
lighter  and  therefore  more  economical  machines  and  engines  than 
those  of  ordinary  steel.  Many  turbines  actuated  by  water,  steam 
or  gas,  are  best  operated  at  speeds  forbidden  to  common  steel, 
which  would  fly  to  pieces  under  the  centrifugal  stress  exerted, 
yet  these  speeds  are  quite  feasible  and  safe  when  nickel  steel  is 
employed.  This  alloy  brings  nearer  the  day  of  mechanical  flight, 

1  Henry  Marion  Howe,  "Iron,  Steel  and  Other  Alloys."    Second  edition. 
Cambridge,  Mass.,  Albert  Sauveur,  1906. 


HEAT  TREATMENT  167 

first  promising  to  transportation  on  land  and  sea  engines  increased 
in  power  while  much  diminished  in  weight.  In  exceptional  cases, 
where  the  expense  may  be  borne,  we  may  expect  soon  to  see  nickel 
steel  used  for  higher  towers,  longer  bridge-spans,  thinner  boilers, 
than  those  of  to-day.  Part  of  the  bridge  crossing  Blackwell's 
Island,  New  York,  is  built  of  nickel  steel.  Even  with  costs  at 
their  present  plane,  it  is  worth  while  for  the  designer  of  machinery 
to  remember  that  friction  is  reduced  when  masses  become  smaller, 
power  for  power.  It  is  found  profitable,  for  instance,  to  use 
r.ickel  steel  for  the  cylinders  of  automobiles  of  high  power. 

In  many  tools  and  implements  two  different  kinds  of  steel  are 
united  with  decided  gain.  Thus  the  cutting  edge  of  a  cold  chisel 
is  hard  and  brittle,  while  its  shank,  much  less  hard,  is  tough  and 
able  to  resist  the  shocks  it  receives.  So  also  a  projectile  is  hard- 
ened at  its  point  and  nowhere  else.  Plowshares  are  often  made 
very  hard  on  their  surfaces,  with  a  backing  which  is  comparatively 
soft  but  elastic  enough  to  suffer  no  harm  in  the  blows  dealt  by 
rough  ground  and  stones.  One  of  the  drawbacks  in  the  use  of 
steel  is  its  liability  to  corrosion.  An  alloy  of  30  per  cent,  nickel 
and  70  per  cent,  steel  has  proved  to  be  corrodible  in  but  slight 
measure,  affording  a  material  of  great  value  to  the  arts. 

While  the  chemical  composition  of  a  steel  is  of  prime  impor- 
tance, the  quality  of  the  steel  will  next  depend  upon  its  heat  treat- 
ment   in    manufacture.     The    temperature    to 
which   heating  is   carried,   the   period   during     Heat  Treatment, 
which  it  is  maintained,  the  rate  at  which  cool- 
ing takes  place,  and  the  circumstances  of  cooling,  each  has  its 
effect  on  the  character  of  the  product.     It  is  chiefly  in  this  field 
that  the  steel-maker  within  wide  limits  is  able  to  turn  out  an  alloy 
either  hard  or  soft,  brittle  or  ductile,  tenacious  or  weak,  at  pleas- 
ure.   While  much  has  been  learned  within  the  past  few  years  as 
to  the  proper  treatment  of  steel  by  heat,  much  still  remains  to  be 
discovered. 

To  quote  typical  instances  from  Professor  Henry  Marion  Howe, 
of  Columbia  University,  New  York:— "In  the  case  of  steel  with 
less  than  0.33  per  cent,  of  carbon  the  temperature  from  which  slow 
cooling  occurs  appears  to  have  little  influence  on  the  tensile 
strength ;  but  it  is  the  general  belief  that  if  that  temoerature  ap- 


168  PROPERTIES— STEEL 

preaches  the  melting-point,  the  tensile  strength  decreases.  In 
the  case  of  higher-carbon  steel,  the  tensile  strength  at  first  in- 
creases as  the  temperature  from  which  slow  cooling  occurs  rises 
to  800°,  or  even  to  900°  or  1000°  C.  Then,  after  varying  some- 
what, it  falls  off  very  abruptly  in  the  case  of  steel  of  0.50  per  cent, 
of  carbon,  when  that  temperature  approaches  1400°. 'J1 

For  rock  drills,  cold  chisels,  milling  and  other  tools  it  is  neces- 
sary to  use  steel  carefully  tempered,  so  that  brittleness  is  greatly 
reduced  while  considerable  hardness  and  cut- 

T  Annealin  ^^  tin^  Power  remam-  Other  changes  of  proper- 
ties, as  remarkable,  follow  upon  subjecting 
steel  to  greater  heat  than  that  used  for  tempering.  Says  Profes- 
sor Roberts-Austen :— "Three  strips  of  steel  identical  in  quality 
are  taken.  By  bending  one  it  is  shown  to  be  soft;  if  it  is  heated 
to  redness  and  plunged  in  cold  water  it  will  become  hard  and 
will  break  on  any  attempt  to  bend  it.  The  second  strip,  after  heat- 
ing and  rapid  cooling,  if  again  heated  to  about  the  melting  point 
of  lead,  will  at  once  bend  readily,  but  will  spring  back  to  a 
straight  line  when  the  bending  force  is  removed.  The  third  piece 
may  be  softened  by  being  cooled  slowly  from  a  bright  red  heat, 
and  this  will  bend  easily  and  remain  distorted.  The  metal  has 
been  singularly  altered  in  its  properties  by  comparatively  simple 
treatment,  and  all  these  changes,  it  must  be  remembered,  have 
been  produced  in  a  solid  metal  to  which  nothing  has  been  added, 
and  from  which  nothing  has  been  taken  away." 

It  is  the  comparative  slowness  of  cooling  in  oil,  the  greater 
slowness  of  cooling  in  air,  that  make  these  by  far  the  best  tem- 
pering processes,  because  the  molecular  re-arrangement,  in  which 
tempering  consists,  requires  time.  Often  the  critical  temperature, 
at  which  a  desired  re-arrangement  takes  place,  is  declared  by  the 
metal  losing  all  power  of  response  to  a  magnet :  this  fact  affords 
the  steel-maker  welcome  aid ;  he  has  only  to  shut  off  heat  as  soon 
as  his  steel  ceases  to  attract  a  magnet  and  plunge  the  steel  into 
water  in  order  to  obtain  the  hardness  he  wishes. 

The  complex  phenomena  of  heat  treatment  in  steel  manufacture 


1ln  his  "Iron,  Steel  and  Other  Alloys."    Second  edition.    Published  by 
Albert  Sauveur,  Cambridge,  Mass.,  1906. 


INVAR  169 

are  fully  discussed  by  Professor  H.  M.  Howe,  in  his  "Iron,  Steel 
and  Other  Alloys,"  second  edition,  1906. 

In  another  chapter  of  this  book  a  word  is  said  as  to  the  form 
of  rails  at  which  Mr.  P.  H.  Dudley  has  arrived  as  the  outcome 
of  years  of  experiment.    He  thus  describes  the 
properties  which  the  steel  should  possess  by    Steel  for^Railroad 
virtue  of  due  chemical  composition  and  proper 
heat  treatment : — 

"Ductility  to  ensure  power  to  resist  the  shock  of  the  driving- 
wheels,  so  that  the  steel  may  not  break;  resistance  to  abrasion, 
that  it  may  not  wear  out ;  and  high  limit  of  elasticity,  that  it  may 
not  take  a  permanent  set  and  be  bent  into  a  series  of  waves  be- 
tween its  supporting  ties,  by  the  enormous  pressures  which  the 
wheels  of  to-day  throw  upon  it.  The  best  composition  is  carbon 
0.55  to  0.60  per  cent.,  silicon  o.io  to  0.15,  manganese  1.20,  sulphur 
under  0.06,  phosphorus  under  0.06 ;  with  50,000  to  60,000  granula.- 
tions  to  the  square  inch.  More  granulations,  or  fewer,  mean  an 
increase  of  brittleness  in  the  steel."1 

While  the  great  strength  of  steel  makes  it  of  pre-eminent 
value  in  the  arts,  steel  in  the  huge  dimensions  of  modern  roofs 
and  bridges  has  the  demerit  of  expanding  with 
heat  and  contracting  with  cold  in  a  troublesome       Invar :  A  Steel 
degree.     A  notable  case  is  that  of  the  steel        Invariable  in 

rails  on  the  elevated  railroad  of  New  York.         ™™cn*i°ns 

Whether  Warmed 
If  this   fault,  common   to  all   metals,   can   be          or  Cooled. 

materially  reduced  or  abolished,  then  steel 
enters  upon  a  new  field  of  golden  harvests.  Here,  by  dint  of 
acumen  and  skill  the  goal  has  been  reached  by  M.  Charles 
Edouard  Guillaume,  of  the  International  Bureau  of  Weights  and 
Measures  in  Paris.  A  few  years  ago  he  began  investigating  the 
singular  magnetic  qualities  of  nickel-steels.  Then  in  studying 
expansibility  by  heat  he  discovered  that  when  the  nickel  was  in- 
creased to  36.2  per  cent,  the  alloy  was  almost  indifferent  to 
changes  of  temperature,  expanding  but  one  part  in  one  million 
when  warmed  from  zero  to  i°  Centigrade.  Because  of  this  in- 

1  Henry  Marion  Howe,  "Iron,  Steel  and  Other  Alloys."  Second  edition. 
Published  by  Albert  Sauveur,  Cambridge,  Mass.,  1906.  And  a  note  from 
Mr.  P.  H.  Dudley  to  the  author,  May  2,  1906. 


170  PROPERTIES— STEEL 

sensibility,  the  alloy  at  the  suggestion  of  Professor  Thury  is 
named  invar.  In  observations  of  invar  which  extended  through 
six  years,  an  elongation  of  one  part  in  100,000  was  detected ; 
subsequently  its  changes  of  length  each  year  seemed  less  than 
one-millionth.  This  slight  inconstancy  may  be  overcome  by 
further  experiment;  in  the  meantime  while  invar  is  not  available 
for  standards  of  length  o.f  the  first  order,  such  as  those  of  the 
Bureau  of  Standards  at  Washington,  there  is  a  vast  and  useful 
field  for  the  alloy.  It  offers  itself  for  secondary  standards,  to  be 
compared  at  intervals  with  primary  standards  at  Washington  or 
.other  capitals  o'f  the  world. 

A  leading  application  will  be  in  surveying.  Already  wires  of 
invar  have  been  employed  by  the  Survey  of  France  with  the  ut- 
most success,  dispensing  with  the  burdensome  apparatus  for- 
.merly  needed  in  compensating  variations  due  to  temperature. 
With  invar  wires  ten  men  have  advanced  at  the  rate  of  five 
kilometers  a  day ;  ten  years  before,  with  ordinary  steel  meas- 
ures, fifty  men  advanced  one  half  a  kilometer,  that  is,  with  but 
one  fiftieth  as  much  efficiency. 

In  time-keeping  invar  is  likely  to  be  as  valuable  as  in  survey- 
ing. At  the  Bureau  of  Standards  and  the  Naval  Observatory 
at  Washington,  pendulums  of  invar  have  been  adopted  with 
gratifying  results.  In  ordinary  watches  and  clocks  the  alloy  will 
banish  the  compensating  devices  now  requisite,  of  brass  and  steel 
which  expand  with  heat  and  shrink  with  cold.  For  chronometers 
of  the  highest  grade  it  is  desirable  that  invar  be  improved  with 
respect  to  its  stability,  an  improvement  which  appears  to  be  highly 
probable. 

One  other  discovery  by  M.  Guillaume  deserves  a  word.  He 
has  found  a  nickel-steel  which  when  warmed  has  the  same  ex- 
pansibility as  glass,  so  that  it  may  displace  platinum  wire  in  lead- 
ing an  electric  current  into  an  incandescent  lamp,  a  Crookes'  tube 
or  similar  illuminator.  More  singular  still  is  another  of  his 
nickel-steels  which  shrinks  slightly  when  warmed,  holding  out 
the  hope  of  finding  an  alloy  which  will  neither  shrink  nor  ex- 
pand as  its  temperature  rises.  With  such  a  substance,  of  trust- 
worthy stability,  the  arts  would  have  a  working  material  of  in- 
estimable value  for  theodolites,  frames  for  microscopes  and  tele- 
scopes, and  cameras  for  exact  picturing. 


HIGH-SPEED  TOOL  STEELS          171 

The  magnetic  properties  of  steel,  to-day  of  supreme  impor- 
tance, have  for  ages  excited  curiosity.  As  long  ago  as  1774,  Rin- 
man  observed  that  steel  alloyed  with  man- 
ganese is  non-magnetic.  Here  was  a  material  Manganese  Steel. 
for  time-pieces  which  would  free  them  from 
magnetic  derangement.  In  the  hands  of  Mr.  R.  A.  Hadfield,  of  the 
Hecla  Works,  Sheffield,  England,  manganese  steel  has  been  pro- 
duced in  remarkable  varieties.  As  the  proportion  of  manganese 
is  increased,  the  alloys  manifest  singular  changes  in  their  prop- 
erties. When  the  manganese  is  four  to  six  per  cent.,  and  the 
carbon  less  than  one-half  per  cent.,  the  alloy  is  brittle  enough  to 
be  readily  powdered  by  a  hand  hammer.  When  the  proportion  of 
manganese  is  doubled,  the  alloy  displays  great  strength,  which 
reaches  its  maximum  when  the  manganese  is  fourteen  per  cent. 
No  other  material  approaches  manganese  steel  in  its  ability  to 
resist  abrasion;  it  outwears  ordinary  steel  four  times,  much  re- 
ducing the  need  for  repairs,  renewals,  or  pauses  in  work  while 
worn-out  parts  are  being  replaced.  It  gives  equally  good  service 
as  the  pins  and  bushings  of  dredges  of  the  bucket-ladder  type, 
lifting  gold-bearing  gravels  and  sands.  It  is  used  for  centrifugal 
pumps  in  dredging  sandy  harbors,  slips,  or  ponds,  where  the  grit 
borne  in  the  water  plays  havoc  with  ordinary  steel  surfaces.  In 
ore-crushing  manganese  steel  is  particularly  effective;  a  pair  of 
jaws  built  of  it  have  crushed  21,000  tons  of  flinty  ore  and  were 
still  good  for  4,000  to  6,000  tons  more,  while  the  best  chilled  iron 
plates  failed  to  crush  as  little  as  4,000  tons. 

This  alloy  is  so  hard  that  it  cannot  be  machined  or  drilled  by 
ordinary  means ;  it  must  be  treated  by  emery  or  carborundum 
wheels.  Yet  it  is  so  malleable  that  it  can  be  used  for  rivets  when 
headed  cold.  It  is  so  tough  that  it  may  be  bent  and  twisted  at 
will  without  rupture,  so  that  it  forms  railroad  switches,  frogs, 
and  crossings  of  great  durability. 

Until  1868  the  steel  tools  used  in  lathes  and  drills,  planers  and 
so  on,  were  limited  to  the  moderate  pace  at  which  they  remained 
cool  enough  to  keep  their  temper.    Beyond  that 
quiet    gait    they    became    worthless,    snapped     Hi£h-sPeed  Tool 
apart,  or  melted  as  if  wax.     In  1868  Robert 
Forester  Mushet,  of  the  Titanic  Steel  and  Iron  Company,  Cole- 
ford,  England,  discovered  an  alloy  of  steel,  tungsten  and  man- 


172  PROPERTIES— STEEL 

ganese  which  took  rough  cuts  at  a  depth  and  with  a  speed  un- 
known before.  This  alloy,  because  hardened  simply  in  air,  was 
called  "air-hardening"  or  "self-hardening."  Thirty  years  after- 
ward at  the  Bethlehem  Steel  Works,  Pennsylvania,  a  tool  of  this 
steel  was  heated  to  what  was  feared  to  be  a  ruinously  high  tem- 
perature; experiment  proved  that  the  tool  could  be  used  at  a 
heat,  and  therefore  at  a  speed,  never  attained  before  in  the  work- 
shop. From  that  hour  hundreds  of  investigators  have  proceeded 
to  combine  steel  with  tungsten  in  various  percentages,  adding 
manganese,  molybdenum,  chromium,  silicon,  and  vanadium.  Of 
these  ingredients  much  the  most  important  are  tungsten  and 
molybdenum.  Particular  pains  must  be  taken  thoroughly  to  an- 
neal the  alloy  when  worked  into  bars. 

As  to  the  gain  introduced  by  high-speed  tool  steels  let  Mr. 
J.  M.  Gledhill  testify  from  the  experience  of  the  Sir  W.  G.  Arm- 
strong, Whitworth  &  Company's  works  at  Manchester : — 

"Formerly  where  forgings  were  first  made  and  then  machined 
with  ordinary  self-hardening  steel,  a  production,  from  bars 
eighteen  and  one  half  by  six  and  five  eighth  inches,  of  eight  bolts 
in  ten  hours  was  usual.  With  the  new  steel  forty  similar  bolts 
from  the  rolled  bar  are  now  turned  out  in  the  same  time,  further 
abolishing  the  cost  of  first  rough  forging  the  bolt  to  form.  The 
speed  is  1 60  feet  a  minute,  the  depth  of  cut  three-quarter  inch, 
of  feed  1/32  inch,  the  weight  removed  from  each  bolt  sixty-two 
pounds,  or  2,480  pounds  per  day,  the  tool  being  ground  only  once 
in  that  time.  This  is  a  fairly  typical  case.  Just  as  striking  is  the 
behavior  of  this  steel  in  twist  drills,  which  supersede  the  punch- 
ing process  by  passing  through  stacks  of  thin  steel  plates  quite  as 
swiftly  and  economically  as  a  punch,  while  avoiding  the  liability 
to  distress  which  accompanies  the  action  of  a  punch." 

With  the  quickening  of  pace  due  to  these  steels,  the  designer 
is  asked  to  remodel  machine  tools  so  that  they  may  stand  up 
against  new  pressures  and  speeds.  A  lathe  thus  re-patterned  is 
mentioned  by  Mr.  Gledhill :  it  absorbs  sixty-five  horse  power  as 
against  twelve  formerly,  and  has  a  belt  trebled  in  width  so  as  to 
measure  twelve  inches.  Mr.  Oberlin  Smith  expects  high-speed 
steel  to  have  other  effects  on  machine  design  than  the  conferring 
of  new  strength :  he  looks  for  a  rivalry  keener  than  ever  between 


ELECTRO-MAGNETS  173 

rotary  and  reciprocating  tools.  In  his  judgment  the  milling  tool, 
which  can  be  speeded  indefinitely,  will  encroach  more  and  more 
on  the  planer,  limited  as  the  planer  is  by  its  movement  being  to 
and  fro. 

When  work  on  cast  iron  must  proceed  at  the  utmost  pace,  a  jet 
of  air,  delivered  to  the  chips  with  force  enough  to  clear  them  off 
as  fast  as  they  are  formed,  enables  the  speed  to  be  quickened, 
while,  at  the  same  time,  the  life  of  the  cutter  is  lengthened.1 

In  electrical  art  the  alloy  employed  for  electro-magnets  should 
be  permeable  by  magnetism  fully  and  easily,  otherwise  dynamos 
and  motors  will  waste  energy  as  their  magnet- 
ism  is    constantly    gained,    lost,    or    reversed.  Alloys  for 
Once  more  the  experimenter  is   Mr.   Robert    Electro-Magnets. 
A.    Hadfield   of    Sheffield,    who    produces    an 
excellent  alloy  by  uniting  iron  with  2.75  per  cent,  silicon,   .08 
per  cent,  manganese,  .03  per  cent,  sulphur,  .03  per  cent,  phos- 
phorus.   This  alloy  is  improved  by  being  heated  to  between  900° 
and  1100°  C,  followed  by  quick  cooling;  then  being  reheated  to 
between  700°  to  800°  C.,  and  cooled  very  slowly. 

Iron  is  largely  used  as  an  electrical  conductor,  so  that  it  is  well 
to  know  how  its  conductivity  is  affected  by  ordinary  admixtures. 
In  experiments  with  sixty-eight  specimens,  Professor  W.  F.  Bar- 
rett alloyed  iron  separately  with  carbon,  aluminium,  silicon,  chro- 
mium, manganese,  nickel,  cobalt,  and  tungsten.  In  every  case 
there  was  a  loss  of  conductivity,  and  usually  in  a  degree  pro- 
portioned to  the  atomic  weight  of  the  added  ingredient.  Between 
one  element  and  another  there  was  often  a  wide  disparity  of 
effect.  For  example,  in  admixtures,  each  of  one  per  cent.,  tung- 
sten increased  the  resistance  of  a  conductor  by  two  per  cent., 
while  aluminium  did  seven- fold  as  much  harm. 

We  have  so  long  been  accustomed  to  thinking  that  there  must 
be  iron  in  everything  magnetic  that  we  hear  with  astonishment 
that  metals  each  insusceptible  of  magnetism,  when  united  strongly 
display  this  property.  Such  is  the  discovery  of  Mr.  Fr.  Heusler, 

1The  foregoing  pages  on  steel  have  been  revised  by  Professor  Bradley 
Stoughton,  of  the  School  of  Mines,  Columbia  University,  New  York.  He 
contributes  at  the  end  of  this  chapter  a  brief  list  of  books  for  the  reader 
who  may  wish  to  know  something  of  the  literature  of  iron  and  steel. 


174  PROPERTIES— ALLOYS 

of  Dillenburg,  near  Wiesbaden.  He  noticed  one  day  that  an  alloy 
of  manganese,  tin,  and  copper  adhered  to  a  tool  which  he  had 
accidentally  magnetized.  In  the  course  of  ex- 
Magnetic  Alloys  periments  Mr.  Heusler  found  that  carbon,  sili- 
of  Non-Magnetic  con,  and  phosphorus  did  not  confer  magnetism; 
Ingredients.  while  arsenic,  antimony,  and  bismuth  did 
so,  all  three  metals  being  diamagnetic, 
that  is,  placing  themselves  at  right  angles  to  a  common  steel 
magnet  above  which  they  are  freely  suspended.  An  alloy  of  re- 
markable magnetic  strength  was  composed  of  copper  61.5  per 
cent.,  manganese  23.5  per  cent.,  and  aluminium  15  per  cent.  This 
alloy  is  brittle  and  considerable  changes  of  temperature  but 
slightly  affect  its  magnetism.  When  a  little  lead  is  added  magnet- 
ism disappears  between  60°  and  70°  C.  This  alloy  therefore  is 
magnetic  when  placed  in  cold  water ;  when  the  water  is  heated  the 
magnetism  disappears  before  the  water  boils,  only  to  reappear 
when  the  water  cools.  The  main  interest  of  these  discoveries  is 
that  the  new  alloys  bridge  the  gap  betwixt  magnetic  and  dia- 
magnetic bodies,  that  is,  they  join  the  iron,  nickel,  and  cobalt 
group,  which  place  themselves  along  the  line  of  a  magnetic  field, 
with  the  diamagnetic  elements;  bismuth,  antimony,  zinc,  tin,  lead, 
silver,  and  arsenic,  which  place  themselves  at  right  angles  to  the 
lines  of  a  magnetic  field.  We  have  been  accustomed  to  suppose 
that  magnetism  is  a  property  possessed  by  only  a  few  elements; 
these  alloys  show  us  that  magnetism  may  arise  as  a  result  of 
grouping  atoms,  none  of  which  by  itself  has  any  magnetism  what- 
ever. Indeed  it  may  be  possible  to  make  an  alloy  more  magnetic 
than  iron,  furnishing  the  electrician  with  electro-magnets  of  new 
power. 

We  have  briefly  glanced  at  recent  progress  in  the  art  of  alloy- 
ing in  so  far  as  it  has  produced  steels  of  new  strength,  elasticity, 
or  hardness;  new  ability  to  resist  abrasion  or 
^gh  temperatures,  new  capacity  for  magnet- 
ism, new  indifference  to  changes  of  tempera- 
ture as  affecting  dimensions.  Alloying  has  of  late  years  conferred 
other  gifts  upon  industry,  of  which  one  example  may  be  cited 
from  among  many  of  equal  importance.  Friction  levies  so 
grievous  a  tax  upon  the  mechanic  and  the  engineer  that  they  are 


MINUTE  ADMIXTURES  175 

quick  to  seize  upon  any  material  for  bearings  which  reduces 
friction.  As  the  result  of  extensive  experiments  Dr.  C.  B.  Dudley 
recommends  an  alloy  of  tin,  copper,  a  little  phosphorus,  with  ten 
to  fifteen  per  cent,  of  lead.  He  finds  the  loss  of  metal  by  wear 
under  uniform  conditions  diminishes  as  the  lead  is  increased  and 
the  tin  diminished. 

We  have  seen  how  remarkably  the  properties  of  iron  are  af- 
fected by  minute  additions  of  carbon  which  may  be  assumed  to 
enter  into  chemical  union  with  the  metal.  The 
properties  of  other  metals  may  be  influenced  Influence  of 
by  minute  quantities  of  added  elements,  al-  Admixtures 
though  in  quantities  so  small  as  to  preclude 
the  possibility  of  their  forming  ordinary  chemical  compounds. 
It  by  no  means  follows,  however,  that  the  atom  of  an  added 
element  does  not  exert  a  direct  influence.  In  Professor  Roberts- 
Austen's  laboratory,  in  London,  two  ladles  were  filled  with  ex- 
ceptionally pure  bismuth ;  into  one  ladle  a  tiny  f ragment  of  tel- 
lurium was  placed.  The  ladles  were  poured  each  into  a  separate 
mold,  and  when  the  metal  became  cold  it  was  fractured  by  a  ham- 
mer. The  bismuth  to  which  the  tellurium  was  added  had  become 
minutely  crystalline;  while  that  which  remained  pure  had  crys- 
tallized in  broad  mirror-like  planes.  One  reflected  light  as  a 
mirror;  the  other,  containing  the  tellurium,  scattered  the  light  it 
received.  With  no  guidance  but  that  of  mere  inspection,  one 
would  have  said  that  the  two  substances  were  distinct  elements, 
and  yet  the  only  difference  was  that  one  contained  1/2000  part  of 
tellurium  and  the  other  no  tellurium  at  all. 

Submarine  telegraphy  presents  us  with  a  case  as  striking :  were 
its  copper  wire  to  contain  but  one-thousandth  part  of  bismuth, 
the  line  would  be  so  much  reduced  in  conductivity  as  to  be  com- 
mercially worthless :  quite  as  harmful  are  mixtures  of  antimony. 
In  coining,  the  addition  to  gold  of  one  five-hundredth  part  by 
weight  of  bismuth  produces  an  alloy  which  crumbles  under  the 
die  and  refuses  to  take  an  impression.  In  the  manufacture  of 
such  dies  it  is  necessary  to  employ  a  steel  containing  0.8  to  I  per 
cent,  of  carbon  and  no  manganese.  It  is  usual,  says  Professor 
Roberts-Austen,  to  water-harden  and  temper  it  to  a  straw  color, 
and  a  really  good  die  will  strike  40,000  coins  without  being 


176  PROPERTIES 

fractured  or  deformed,  but  if  the  steel  contains  o.l  per  Cent,  too 
much  carbon,  it  would  not  strike  100  pieces  without  cracking,  and 
if  it  contained  0.2  per  cent,  too  little  carbon,  it  would  probably 
be  hopelessly  distorted  and  its  engraved  surface  destroyed  in  the 
attempt  to  strike  a  single  coin.  As  in  coining  so  in  steam- 
engineering.  A  little  arsenic  added  to  copper  improves  it  for  the 
fire-boxes  of  locomotives.  Boilers  of  old,  formed  of  copper 
slightly  admixed  with  sulphur,  lasted  longer  than  modern  boilers 
built  of  copper  free  from  sulphur.  Antimony  behaves  like 
arsenic,  and  in  due  proportion  strengthens  copper;  bismuth,  on 
the  contrary,  weakens  copper,  and  a  perceptible  effect  is  wrought 
by  a  mere  trace.  Nickel  is  made  malleable  by  adding  extremely 
small  quantities  of  phosphorus,  magnesium,  or  zinc. 


BOOKS  ON  IRON  AND  STEEL 
Chosen  and  annotated  by  Professor  Bradley  Stoughton,  School 

Of  Mines,  Columbia  University,  New  York.  (Graduated  Yale  Univer- 
sity, 1893,  as  Ph. B.  In  1896  Assistant  in  Mining  and  Metallurgy  at  Massachusetts  Insti- 
tute of  Technology,  Boston,  where  he  received  the  degree  of  B.S.  In  1898-99,  metallurgist 
of  South  Works.  Illinois  Steel  Co.,  South  Chicago.  Superintendent  in  1900  of  steel  foundry. 
Briggs-Seabury  Gun  and  Ammunition  Co.,  Derby,  Conn.  Manager  of  Bessemer  plant, 
Benjamin  Atha  &  Co.,  Newark,  N.  J.,  In  1901.  Instructor  in  metallurgy,  Columbia  Uni- 
versity, 1902-03.  Next  year  became  Adjunct  Professor  of  Metallurgy,  Columbia  University 
and,  as  consulting  metallurgist,  entered  the  firm  of  Howe  &  Stoughton,  New  York.) 

BALE,  GEORGE  R.     Modern  Foundry  Practice.     Part  I,  1902.     Part  II,  1006. 

London,  Technical  Publishing  Co.    3^.  6d,  each. 

An  admirable  work,  the  only  one  covering  the  whole  field.  The  author 
thoroughly  understands  his  subject,  and  writes  most  intelligibly.  The 
principles  underlying  every  detail  of  practice  are  clearly  explained. 

Part  I  deals  with  foundry  equipment,  materials  used,  furnaces  and 
processes,  describes  blowers,  ladles,  cranes,  hoists,  cupola,  air  furnaces, 
drying  ovens,  dry  and  green  sand,  the  manufacture  of  chilled  castings  and 
malleable  iron  castings. 

Part  II  takes  up  machine  molding,  physical  properties,  the  effects  pro- 
duced by  various  ingredients,  the  principles  of  mixing  irons,  cleaning 
castings.  Costs  are  considered  in  conclusion. 


BOOKS  ON  IRON  AND  STEEL 

BELL,  SIR  ISAAC  LOWTHIAN.  Principles  of  the  Manufacture  of  Iron  and 
Steel.  London,  George  Routledge  &  Sons,  1884.  722  pp.  2is. 
A  classic.  Like  "Chemical  Phenomena  of  Iron  Smelting,"  by  the  same 
author,  now  out  of  print  and  rare,  it  will  never  be  replaced  by  a  new 
book  in  the  metallurgist's  library,  although  somewhat  out  of  date.  Deals 
with  principles  ever  important,  while  our  knowledge  of  them  increases 
constantly.  Begins  with  a  brief  history,  then  passes  to  the  direct  processes 
for  the  production  of  iron  and  steel.  Then  follow  sections  on  the  funda- 
mental principles  of  blast  furnace  operation,  and  a  study  of  the  refining 
of  pig-iron,  or,  in  other  words,  the  principles  of  the  conversion  of  pig- 
iron  into  wrought  iron  and  steel.  For  recent  metallurgical  practice,  some 
later  book  is  to  be  preferred. 

CAMPBELL,  HARRY  HUSE.  Manufacture  and  Properties  of  Iron  and 
Steel.  2d  edition.  New  York,  Engineering  and  Mining  Journal,  1903. 
839  PP-  $5-00. 

Mr.  Campbell  is  a  careful  and  deep  thinker.  He  is  well  known  as  the 
successful  manager  of  a  large  and  important  steel  works.  Out  of 
abundant  knowledge,  gathered  in  long  experience  and  study,  he  gives 
in  this  book  much  valuable  information.  Details  of  the  various  furnaces 
and  their  operations  are  frequently  lacking,  but  as  a  comparative  study 
of  leading  methods  of  steel-making,  and  of  the  commercial  conditions 
involved,  this  work  has  no  equal. 

HARFORD,  F.  W.  Metallurgy  of  Steel.  With  a  section  on  the  Mechan- 
ical treatment  of  Steel,  by  F.  W.  Hall.  Revised  edition.  London, 
Charles  Griffin  &  Co.,  1905.  792  pp.  25^. 

This  exhaustive  treatise  is  the  best  of  its  kind.  Abounds  with  valuable 
information  on  furnaces  and  their  working,  on  the  effects  of  different 
impurities  in  steel.  On  the  shaping  of  steel  mechanically  it  is  the  only 
complete  treatise.  This  work  deals,  however,  chiefly  with  English  prac- 
tice, while  American  practice  is  larger  and  more  progressive. 

HOWE,  HENRY  M.    Iron,  Steel  and  Other  Alloys.    2d  edition,  slightly  re- 
vised.   Boston,  A.  Sauveur,  1906.     18+495  pp.    $5.oa 
The  best  and  most  complete  work  on  the  modern  theory  of  the  consti- 
tution of  steel  by  the  highest  living  authority.    Can  be  readily  understood 
by  any  one  having  a  slight  knowledge  of  chemistry.     In  addition  to  the 
study  of  iron  and  steel  as  metals,  brief  but  satisfactory  chapters  in  manu- 
facture are  included. 

HOWE,  HENRY  M.    Metallurgy  of  Steel.    Vol.  I.    4th  edition.     New  York, 
Engineering  and  Mining  Journal,  1890.     385  pp.     $10.00. 
Still  recognized  the  world  over  as  the  standard  authority;  every  book 

written  on  its  theme  since  1890  builds  upon  this  work  as  the  source  of 


178  PROPERTIES 

highest  reference.  Devoted  chiefly  to  the  effects  of  different  impurities, 
and  of  treatment,  on  steel.  The  crucible  and  Bessemer  processes  are  de- 
scribed at  some  length.  Not  a  work  for  general  readers. 

MELLOR,  J.  W.  Crystallization  of  Iron  and  Steel :  an  Introduction  to  the 
Study  of  Metallography.  London  and  New  York,  Longmans,  Green  & 
Co.,  1905.  154  pp.  5s.  $1.60. 

Reprinted  lectures  giving  an  excellent  popular  account  of  the  consti- 
tution and  nature  of  cast  iron  and  steel.  Includes  right  and  wrong 
methods  of  annealing,  hardening  and  tempering  steel,  and  their  micro- 
scopic examination.  The  information  is  presented  in  a  terse  and  at- 
tractive style.  Any  reader  of  a  scientific  turn  will  find  profit  in  this  book. 

SEXTON,  A.   HUMBOLDT.     Outline  of  the   Metallurgy  of  Iron  and   Steel. 

Manchester,  Scientific  Publishing  Co.,  1902.     16^. 

The  best,  because  most  recent  of  the  good  elementary  text-books  on 
iron  and  steel.  It  is  behind  the  times  in  regard  to  American  practice, 
but  contains  a  great  deal  of  important  information,  clearly  expressed. 
Covers  iron  ores,  their  physics  and  chemistry,  construction  and  working 
of  the  blast  furnace,  foundry  practice,  puddling,  forging,  the  Bessemer, 
open  hearth  and  crucible  processes,  special  steels,  the  testing  of  steel  and 
protection  from  corrosion.  Its  sketch  of  the  structure  and  heat  treatment 
or  iron  and  steel  is  very  incomplete. 

SWANK,  JAMES  M.  Short  History  of  the  Manufacture  of  Iron  in  all 
ages,  particularly  in  the  United  States  from  1585  to  1885.  2d  edition. 
Philadelphia,  American  Iron  and  Steel  Association,  1894.  42&  pp.  $5.00. 
The  best  historical  account  of  iron  and  steel  manufacture,  written  in 

an  interesting  manner.     So  carefully  systematized  that  the  history  of  any 

branch  of  the  subject  may  be  studied  independently. 


SWANK,  JAMES  M.    Directory  of  the  Iron  and  Steel  Works  in  the  United 
States  and  Canada.     Embracing  a  full  description  of  the  blast  furnaces, 
rolling  mills,  steel  works,  tin  plate  and  terne  plate  works,  forges  and 
bloomaries  in  the  United  States;  also  classified  lists  of  the  wire  rod 
mills,  structural  mills,  plate  sheet  and  skelp  mills,  Bessemer  steel  works, 
open    hearth    steel    works,    and    crucible    steel    works.     i6th    edition. 
Philadelphia,  American  Iron  and  Steel  Association,  1904.    $10.00. 
A  Supplement  to  this  directory  contains  a  classified  list  of  leading  con- 
sumers  of  iron   and   steel   in   the   United    States,   corrected   to  January, 
1903.     196  pp.    $5.00. 

The  Penton  Publishing  Co.,  Cleveland,  Ohio,  publish  a  list  of  the  iron 
foundries  in  the  United  States  and  Canada,  mentioning  plants  not  listed 
by  Mr.  Swank,  1906.  $10.00. 


BOOKS  ON  IRON  AND  STEEL        179 

TURNER,  THOMAS.     Metallurgy  of  Iron  and  Steel.     Edited  by  Prof.  W.  C. 

Roberts-Austen.     Vol.  I,  Metallurgy  of  Iron.     London,  Charles  Griffin  & 

Co.,  1895.     367  pp.     i6s. 

If  but  one  book  is  to  be  chosen,  this  is  the  best  on  ores,  construction  and 
working  blast  furnaces,  the  properties  of  cast  iron,  the  manufacture  and 
properties  of  wrought  iron.  It  also  has  valuable  chapters  on  foundry 
practice,  the  history  of  iron,  blast  furnace  fuels,  forging  and  rolling,  and 
the  corrosion  of  iron  and  steel. 

WOODWORTH,  JOSEPH  V.  Hardening,  Tempering,  Annealing  and  Forging 
of  Steel :  a  treatise  on  the  practical  treatment  and  working  of  high 
and  low  grade  steel.  New  York,  Norman  W.  Henley  &  Co.,  1903. 
288  pp.  $2.50. 

Treats  of  the  selection  and  identification  of  steel,  the  most  modern  and 
approved  processes  of  heating,  hardening,  tempering,  annealing  and  forg- 
ing, the  use  of  gas  blast  forges,  heating  machines  and  furnaces,  the  an- 
nealing and  manufacture  of  malleable  iron,  the  treatment  and  use  of 
self-hardening  steel,  with  special  reference  to  case-hardening  processes, 
the  hardening  and  tempering  of  milling  cutters  and  press  tools,  the  use 
of  machinery  steel  for  cutting  tools,  forging  and  welding  high  grade 
steel  forgings  in  America,  forging  hollow  shafts,  drop-forging,  and 
grinding  processes  for  tools  and  machine  parts. 

It  is  almost  impossible  to  say  which  is  the  best  book  on  the  practice 
treated  in  this  book.  It  has  been  chosen  because  it  contains  much  valu- 
able information  which  has  the  rare  quality  of  not  only  being  useful  in 
the  shop,  but  of  being  accompanied  by  the  reasons  involved.  Copiously 
illustrated.  Many  useful  tables.  For  one  looking  for  general  knowledge 
it  will  be  found  serviceable.  For  the  seeker  who  wishes  special  data  no 
single  book  will  suffice. 

JOURNAL   OF   THE   IRON    AND    STEEL   INSTITUTE.    Edited   by   Bennett   H. 

Brough.     London.     Published   by   the   Institute.        Semiannual.     Each 

number  16  shillings;  mailed  by  Lemcke  &  Buechner,  n  E.  I7th  St.,  New 

York.    $4.50. 

Contains  many  articles  of  importance,  and  abstracts  of  a  large  part 
of  the  current  literature  of  iron  and  steel.  Thus  almost  every  metallurgist 
who  begins  the  study  of  a  new  subject  uses  this  Journal;  he  finds  it  a 
guide  to  the  latest  information  which  has  not  yet  found  its  way  into 
reference  and  text  books. 

REVUE  DE  METALLURGIE.    Edited  by  Henri  Le  Chatelier.      Paris.    Monthly. 

Per  annum,  40  francs;  mailed  by  Lemcke  &  Buechner,  n  E.  I7th  St., 

New  York.    $10.00. 

Most  valuable  for  recent  literature  on  the  constitution  of  iron  and  steel 
and  their  alloys.  Contains  bibliographies  of  works  on  these  subjects. 


CHAPTER  XIV 

PROPERTIES— Continued 

Glass  of  new  and  most  useful  qualities  .  .  .  Metals  plastic  under  pressure 
.  .  .  Non-conductors  of  heat  .  .  .  Norwegian  cooking  box  .  .  .  Aladdin 
oven  .  .  .  Matter  seems  to  remember  .  .  .  Feeble  influences  become 
strong  in  time. 

AS  in  the  case  of  the  aluminium  bronzes  and  nickel  steels, 
alloys  of  the  utmost  value  have  been  formed  by  introducing 
new  ingredients,  often  in  little  more  than  traces,  or  by  modifying 
but  slightly  the  proportions  in  which  ingredients  long  familiar 
have  been  mingled  together.  An  equal  gain 
has  followed  upon  varying  anew  the  composi-  Jena  Glass, 
tion  of  glass.  For  centuries  the  only  materials 
added  to  sand  for  its  melting  pot  were  silicic  acid,  potash,  soda, 
lead-oxide,  and  lime.  As  optical  research  grew  more  exacting 
the  question  arose,  Will  new  ingredients  give  us  lenses  of  better 
qualities?  First  of  all  came  the  demand  for  glasses  which  com- 
bined in  lenses  would  yield  images  in  the  telescope  and  micro- 
scope free  from  color.  In  a  simple  lens,  such  as  that  of  an  ordi- 
nary reading  glass,  we  can  readily  observe  the  production  of 
color  by  a  common  beam  of  light.  The  rays  of  different  colors, 
which  make  up  white  light,  are  refrangible  in  different  degrees, 
so  that  while  the  violet  rays  come  to  a  focus  near  the  lens,  the 
red  rays  have  their  focus  farther  off;  the  images,  therefore,  in- 
stead of  being,  sharply  defined,  are  surrounded  by  faint  colored 
rings.  In  a  telescope  or  microscope  a  simple  lens  would  be  of 
no  value  from  the  indistinctness  of  its  images.  To  correct  this 
dispersion  of  color  a  second  lens  of  opposite  action  is  placed  be- 
hind the  first,  that  is,  a  crown-glass  lens  is  added  to  a  flint-glass 
lens.  (See  cut,  p.  254.)  This  remedy  is  not  quite  perfect  for 
the  reason  that  the  distribution  of  the  spectrum  from  violet  to 

180 


JENA  GLASS  181 

red  varies  with  each  kind  of  glass,  and  in  such  a  way  that  through 
failure  of  correspondence,  color  to  color,  in  a  compound  lens, 
variegated  fringes  of  light,  though  faint,  are  perceptible,  much 
to  the  annoyance  of  the  microscopist,  the  astronomer,  and  the 
photographer. 

With  a  view  to  producing  glasses  which  united  in  compound 
lenses  should  be  color  free,  Rev.  Vernon  Harcourt,  an  English 
clergyman,  in  1834  began  experiments  which  he  continued  for 
twenty-five  years.  By  using  boron  and  titanium  in  addition  to 
ordinary  ingredients  of  glass,  he  produced  lenses  less  troubled  by 
color  than  any  that  had  before  been  made.  His  labors,  only  in 
part  successful,  were  in  1881  followed  by  those  of  Professor  Ernst 
Abbe  and  Dr.  Otto  Schott  at  Jena.  With  resources  provided  by 
the  Government  of  Prussia,  these  investigators  were  able  to  do 
more  for  the  science  and  art  of  glass-making  than  all  the  workers 
who  stood  between  them  and  the  first  melters  of  sand  and  soda. 
They  immensely  diversified  the  ingredients  employed,  carefully 
noting  the  behavior  of  each  new  glass,  how  much  light  it  ab- 
sorbed, how  it  behaved  in  damp  air,  what  strength  it  had,  how  it 
retained  its  original  qualities  during  months  of  keeping,  and  in 
particular  how  variously  colored  rays  were  distributed  through- 
out its  field  of  dispersion.  As  in  the  blending  of  new  alloys  it  was 
found  that  many  of  these  novel  combinations  were  useless.  Of 
the  scores  of  new  glasses  produced  some  were  extremely  brittle, 
others  were  easily  tarnished  by  air,  or  so  soft  as  to  refuse  to  be 
shaped  as  prisms  or  ground  as  lenses.  A  more  systematic  plan  of 
experiment  was  therefore  adopted :  for  the  production  of  new 
glasses  there  were  by  degrees  separately  introduced  in  varied 
quantities,  carefully  measured,  boron,  phosphorus,  lithium,  magne- 
sium, zinc,  cadmium,  barium,  strontium,  aluminium,  berylium, 
iron,  manganese,  cerium,  didymium,  erbium,  silver,  mercury,  thal- 
lium, bismuth,  antimony,  arsenic,  molybdenum,  niobium,  tungsten, 
tin,  titanium,  fluorine,  uranium.  An  early  and  cardinal  discovery 
was  that  the  relation  between  refraction  and  dispersion  may  be 
varied  almost  at  will.  For  example,  boron  lengthens  the  red  end 
of  the  spectrum  relatively  to  the  blue;  while  fluorine,  potassium, 
and  sodium  have  the  opposite  effect.  With  the  distribution  of  the 
diverse  hues  of  the  spectrum  thus  brought  under  control,  there 


1 82  PROPERTIE  S— GL  AS  S 

were  produced  glasses  which,  when  united  as  compound  lenses, 
were  almost  perfectly  color-free,  rendering  images  with  a  new 
sharpness  of  definition.  Yet  more:  in  their  unceasing  round  of 
experiments  Professor  Abbe  and  Dr.  Schott  came  upon  glass  so 
little  absorbent  of  light  that  combinations  of  much  thickness  inter- 
cepted only  a  small  fraction  of  a  beam ;  they  were  indeed  almost 
perfectly  transparent.  This  achievement  is  of  great  importance  to 
the  photographer,  whose  planar  combination  of  six  lenses  may  be 
four  inches  in  thickness.  At  Jena  the  researchers  are  endeavoring 
to  perfect  another  gift  for  the  camera:  they  seek  to  produce 
glasses  each  transmitting  but  one  color,  for  service  in  color- 
photography. 

To  microscopy  they  have  recently  given  lenses  which  completely 
transmit  ultra-violet  rays  so  as  to  photograph  the  diffraction  discs 
of  objects,  such  as  gold  particles  in  colloidal  solutions,  otherwise 
invisible,  because  below  the  resolving  power  of  the  most  powerful 
microscope.  It  is  estimated  that  with  this  new  aid  an  object  but 
1/250,000,000  of  a  millimeter  in  length  may  indirectly  be  brought 
to  view. 

One  ancient  art,  that  of  annealing  glass,  Professor  Abbe  and 
Dr.  Schott  greatly  improved,  eliminating  from  their  products  the 
stresses  which  distort  an  image.  By  means  of  an  automatic  heat- 
regulator,  the  temperature  of  a  batch  of  glass  could  be  kept  stead- 
ily for  any  desired  period  at  any  point  between  350°  and  477°  C., 
or  allowed  to  fall  uniformly  at  any  prescribed  rate.  The  glass 
was  usually  contained  in  a  very  thick  cylindrical  copper  vessel, 
on  which  played  a  large  gas  flame.  The  highest  temperature 
found  necessary  to  banish  stress,  that  is,  to  cause  softening  to 
begin,  was  465°  C.  The  lowest  temperature  required  to  ensure 
complete  hardening  was  about  370°  C.  Thus  the  temperatures  of 
solidification  all  lie  between  370°  and  465°.  This  fall  of  95°  was 
spread  over  an  interval  of  four  weeks,  instead  of  a  few  days  as 
formerly,  with  the  result  that  stress  was  banished  utterly. 

A  practical  example  of  the  benefits  gained  in  the  properties  of 
Jena  glass  is  exhibited  by  its  use  in  measuring  heat.  A  thermom- 
eter of  common  glass  when  first  manufactured  may  tell  the  truth, 
and  in  a  month  or  two  may  vary  from  truth  so  much  as  to  be 
worthless.  The  reason  is  that  the  dimensions  of  the  glass  slowly 


\ 


Photograph  by  liramilk  h  &  Tesch. 


THE  LATE  PROFESSOR  ERNEST  ABBE,  OF  JENA. 


OF  THE 

UNIVERSITY 

OF 


JENA  GLASS  183 

change  day  by  day,  as  in  a  less  degree  do  those  of  many  alloys. 
It  was  one  of  the  aims  of  the  Jena  laboratory  to  produce  a  glass 
which  should  remain  constant  in  its  dimensions  while  exposed  to 
varying  temperatures,  so  that,  made  into  thermometers,  it  would 
be  thoroughly  trustworthy.  Here,  too,  success  was  attained,  so 
that  thermometers  of  Jena  glass  are  found  to  be  reliable  as  are  no 
instruments  of  ordinary  glass.  This  product  is  available  for  astro- 
nomical lenses,  otherwise  liable  to  serious  changes  of  form  as 
exposed  successively  to  warmth  and  cold. 

Heat  was  to  be  staunchly  withstood  not  only  in  moderate  varia- 
tions, but  in  extreme  degrees.  From  time  immemorial  heat  sud- 
denly applied  to  glass  has  riven  it  in  pieces.  Could  art  dismiss 
this  ancient  fault  ?  To-day  a  beaker  from  Jena  may  be  filled  with 
ice  and  placed  with  safety  on  a  gas  flame.  In  its  many  varieties 
this  glass  furnishes  the  chemist  with  clean,  transparent  and  un- 
tarnishing  vessels  for  the  delicate  tasks  of  the  laboratory,  all  of 
singular  indifference  to  heat  and  cold.  Yet  again.  Special  kinds 
of  this  glass  in  chemical  uses  are  attacked  by  cold  or  hot  corrosive 
liquids  only  one-twelfth  to  one- fourth  as  much  as  good  Bohemian 
glass,  the  next  best  material. 

Not  only  to  heat  but  to  light  Jena  glass  renders  a  service.  Glass 
of  ordinary  kinds  when  used  for  the  tubes  of  a  Hewitt  mercury- 
vapor  lamp,  absorbs  a  considerable  part  of  the  ultra-violet  rays 
upon  which  photography  chiefly  depends.  A  Jena  glass  free  from 
this  fault  is  formed  into  Uviol  lamps  of  great  value  in  taking 
photographs,  photo-copying,  and  photo-engraving.  These  lamps 
are  also  employed  in  ascertaining  the  comparative  stability  of  inks 
and  artificial  dyes;  so  intense  is  their  action  that  brief  periods 
suffice  for  the  tests.  Uviol  rays  severely  irritate  the  eyes  and  skin ; 
they  may  prove  useful  in  treating  skin  diseases.  They  moreover 
quickly  destroy  germs.  In  all  these  activities  reminding  us  of 
radium. 

Thus  by  a  bold  departure  from  traditional  methods  in  glass- 
making,  the  eye  receives  aid  from  lenses  more  powerful  and  more 
nearly  true  than  ever  before  swept  the  canopy  of  heaven,  or 
peered  into  the  structure  of  minutest  life.  Meanwhile  instruments 
of  measurement  take  on  a  new  accuracy  and  retain  it  as  long  as 
they  last.  All  this  while  a  material  invaluable  for  its  transparency 


184 


PROPERTIE  S— ME  T  AL  S 


is  redeemed  from  brittleness  and  corrodibility,  and  given  a 
strength  all  but  metallic ;  at  the  same  time  transmitting  light  with 
none  of  the  usual  subtraction  from  its  beams. 

From  glass  let  us  now  turn  to  metals.    It  is  their  tenacity  that 

chiefly  gives  them  value;  this  tenacity  is  usually  accompanied  by 

a  hardness  which  disposes  us  to  regard  nickel, 

0>v"    re^se          for  example,  as  of  a  solidity  quite  unyielding. 

Working.  But  tne  coms  m  our  pockets  prove  that  under 

the  pressure  of  minting  machinery  they  are  as 

impressible  as  wax.    In  molds  and  dies,  each  the  counterpart  of  the 

other,  brass,  bronze,  iron,  steel,  and  tin-plate  take  desired  forms 

as  readily  as  if  paste.  Solid 
though  these  metals  appear 
they  yield  under  severe 
stress  with  a  semi-fluid 
quality.  We  have  long 
had  stamped  kitchen  ware, 
baking  pans,  and  the  like; 
the  principle  of  their  manu- 


facture has  of  late  years 
been  extended  to  ware  of 
more  importance.  Bliss 
power  presses  are  to-day 
turning  out  hundreds  of  articles  which  until  recently  were  either 


Bliss  forming  die.  A,  bed  plate. 
B,  blank-holder.  C,  drawing  punch. 
D,  push-out  plate.  O,  P,  annular 
pressure  surfaces. 


Sizing  or  Finishing  Die 
Redrawing  Die 

Redrawing  Die 


Redrawing  Die 
Drawing  D/e 


6th.  Operaf/on 
4fh.  Operat/on 

3d.Operaf/on 


2d.Operaf/on 
\/sf.Openaf/on 


Bliss  process  of  shell  making. 


PRESSING  METALS 


185 


Mandolin  pressed  in  aluminium. 


slowly  hammered  or  spun  into  form,  pieced  with  solder,  or  shaped 

by  the  gear  cutter  or  the  milling  machine.    These  presses  furnish 

the  United  States  Navy  with  sharp-pointed  projectiles,  some  of 

them  so  large  as  to  demand 

a    million    pounds    pressure 

for    their    production;    they 

make  strong  seamless  drawn 

bottles,  cylindrical  tanks  for 

compressed    air    and    other 

gases,  and  cream  separators 

able    to    withstand    the    bursting   tendency    of    extremely    swift 

rotation. 

Presses  less  powerful  produce  scores  of  parts  for  sewing  ma- 
chines, typewriters,  cash  registers,  bicycles,  and 
so  on ;  or,  at  a  blow,  strike  out  a  gong  from  a 
disc  of  bronze.  Presses  of  another  kind  stamp 
out  cans  in  great  variety,  and  even  a  mandolin 
frame  in  all  its  irregular  curves.  Tubs  are 
quickly  pressed  from  sheets  of  metal ;  a  pair  of 
such  tubs,  tightly  joined  at  their  rims  by  a  double 
seam,  form  a  barrel  impervious  to  oil  or  other 
liquid,  and  hence  preferable  to  a  wooden  barrel.  A  press  operated 
by  a  double  crank  may  be  arranged  to  supersede  the  forging  of 
hammers,  axes,  and  mat- 
tocks. Another  press  at  a 
blow  cuts  out  the  front  for 
a  steel  range.  Still  another 
press  invades  the  foundry, 
producing  excellent  gear 
wheels  for  trolley  cars,  not 
weakened  by  being  cut  from 
a  casting  across  the  grain  of 
the  metal.  Sometimes  the  article  manufactured  requires  a  series 
of  operations,  as  in  the  case  of  a  kettle  cover  with  its  knob.  At 
the  Lalance  &  Grosjean  factory,  Woodhaven,  New  York,  a  Bliss 
press  makes  such  covers  in  a  single  continuous  round.  Another 
press  treats  soft  alloys,  so  that  a  disc  one  inch  in  diameter  when 
hit  by  a  plunger  is  forced  into  the  shape  of  a  tube  suitable  to  hold 
paint  or  oil, 


Pressed  Seam- 
less pitcher. 


Barrel  of  pressed  steel. 


186 


PROPERTIES— METALS 


Range  front  pressed  from  sheet  steel. 


In  large  manufactures  as  in  small  the  hydraulic  forge  has 
wrought  a  quiet  revolution.  If  a  steel  freight  car  were  produced 
by  planing,  turning,  slotting  and  similar  machines,  it  would  be 

much  heavier  and  dearer 
than  as  turned  out  to-day 
from  ingeniously  fashioned 
dies  under  severe  pressure. 
Its  girders  are  molded  of 
the  same  strength  through- 
out with  no  waste  of  mate- 
rial, and  without  rivets; 
corner  pieces  are  avoided; 
stiffeners  are  built  up  from 
the  plates  themselves 
through  the  introduction  of 
ridges  and  depressions  :  and 

in  a  structure  having  the  fewest  possible  parts,  uniform  strength 
is  attained  because  dimensions  everywhere  may  freely  depart 
from  uniformity. 

In  a  vast  manufactory  of  steel  cars, 
of  steel  structural  forms,  steam  has  to 
be  conveyed  long  distances  from  the 
boilers.      Here,    as    in    similar    huge  pressed  paint  tube  and  cover, 
establishments,  or  in  the   heating  of 

towns  and  cities  from  central  stations,  it  is  desirable  to. lose  as 
little  heat  as  possible  by  the  way,  for  undue  waste  means 
enormous  inroads  upon  profits.  There  are 

°ther  reasons  for  wishing  to  keeP  heat  within 
a  steam 'pipe;  much  damage  may  be  done  to 

fruit,  flour  and  other  merchandise  unduly  warmed.  Furthermore 
there  is  a  risk  of  setting  fire  to  woodwork,  paper,  cotton  and  the 
like  fit  has  been  observed  that  after  a  month's  exposure  to  heat 
from  steampipes,  wood  takes  fire  at  a  temperature  which  at  first 
would  not  have  led  to  ignition,  because  then  the  wood  contained  a 
little  moisture.  To  guard  against  loss  and  danger  it  has  long  been 
the  practice  to  cover  steampipes  with  jackets  of  non-conducting 
material,  such  as  mineral-wool,— furnace-slag  blown  into  short 
glassy  fibres  by  a  sharp  blast  of  air.  Felt,  loosely  folded,  also 


NON-CONDUCTORS  OF  HEAT        187 

serves  well.  Many  advertised  claims  for  asbestos  are  not  well 
founded;  this  mineral  is  incombustible  and  is  therefore  useful  in 
thick  curtains  to  separate  a  stage  from  the  auditorium  of  a 
theatre.  But  it  is  a  fairly  good  conductor,  and  for  steampipes 
should  be  used  as  a  direct  covering  of  the  metal  simply  to  keep  an 
outer  and  much  thicker  coat  of  felt  from  being  charred.  What- 
ever the  material  chiefly  employed,  one  point  is  clearly  brought 
out  by  experiment,  namely,  that  the  air  detained  by  the  fibres  of 
a  covering  greatly  aids  in  obstructing  the  passage  of  heat.  Hence 
it  is  well  to  keep  the  materials  from  becoming  compacted  together, 
as  do  ashes  when  moistened.  Asbestos  fibres,  which  are  smooth 
and  glassy,  do  not  take  hold  of  air  as  do  cork  and  wool. 

Professor  J.  M.  Ordway,  of  the  Massachusetts  Institute  of 
Technology,  Boston,  tells  us  that  non-conductors  should  be  of 
materials  that  are  abundant  and  cheap ;  clean,  and  inodorous ;  light 
and  easy  to  apply;  not  liable  to  become  compacted  by  jarring  or 
to  change  by  long  keeping ;  not  attractive  to  insects  or  mice ;  not 
likely  to  scorch,  char  or  ignite  at  the  long-continued  highest  tem- 
perature to  which  they  may  be  exposed ;  not  liable  to  spontaneous 
combustion  when  partly  soaked  in  oil;  not  prone  to  attract 
moisture  from  the  air ;  not  capable  of  exerting  chemical  action  on 
the  surfaces  they  touch.  No  material  combines  all  these  de- 
sirable qualities,  but  a  considerable  range  of  substances  fulfil 
most  of  the  requirements. 

Tests  of  steam-pipe  coverings  at  Sibley  College,  Cornell  Uni- 
versity, and  at  Michigan  University,  have  resulted  as  follows : — 

Relative  Amount  of 
Kind  of  Covering  Heat  Transmitted 

Naked  pipe 100. 

Two  layers  asbestos  pipe,  I  inch  hair  felt,  canvas  cover 15.2 

The  same,  wrapped  with  manila  paper 15. 

Two  layers  asbestos  paper,  i  inch  hair  felt 17. 

Hair  felt  sectional  covering,  asbestos  lined  18.6 

One  thickness  asbestos  board 59.4 

Four  thicknesses  asbestos  paper 50.3 

Two  layers  asbestos  paper   77.7 

Wool  felt,  asbestos  lined  23.1 

Wool  felt  with  air  spaces,  asbestos  lined 19.7 

Wool  felt,  plaster  paris  lined 25.9 


188  PROPERTIES   RELATED 

Relative  Amount  of 
Kind  of  Covering  Heat  Transmitted 

Asbestos  molded,  mixed  with  plaster  paris 31.8 

Asbestos  felted,  pure  long  fibre 20.1 

Asbestos  and  sponge  18.8 

Asbestos  and  wool  felt  20.8 

Magnesia,  molded,  applied  in  plastic  condition 22.4 

Magnesia,  sectional 18.8 

Mineral    wool,    sectional 19-3 

Rock  wool,  fibrous 20.3 

Rock  wool,  felted 20.9 

Fossil  meal,  molded,  ^  inch  thick 29.7 


In  general  the  thickness  of  the  coverings  tested  was  one  inch. 
Some  tests  were  made  with  coverings  of  different  thicknesses, 
from  which  it  would  appear  that  the  gain  in  insulating  power 
obtained  by  increasing  the  thickness  is  very  slight  compared  with 
the  increase  in  cost.1 

Some  properties  of  matter  seem  to  have  family  ties.  Tenacity 
and  conductivity  for  heat,  as  an  example,  go  together;  all  the 
tenacious  metals  as  a  group  are  conducting  as  well.  Conversely, 
the  non-conductors,— felt,  gypsum,  and  the  rest,  are  structurally 
weak.  If  the  inventor  could  lay  hands  on  a  material  able  to  with- 
stand high  pressure  and,  at  the  same  time,  carry  off  waste  fully 
but  little  heat,  he  would  build  with  it  cylinders  for  steam  engines 
much  more  economical  than  those  of  to-day  He  would  also  give 
cooking  apparatus  of  all  kinds  a  covering  which  would  conduce 
to  the  health  and  comfort  of  the  cook,  while,  at  the  same  time, 
heat  would  be  economized  to  the  utmost.  One  of  the  advantages 
of  electric  heat  is  that  it  can  be  readily  introduced  into  kettles 
and  chafing  dishes  surrounded  by  excellent  non-conductors;  the 
result  is  an  efficiency  of  about  ninety-five  per  cent.,  quite  unap- 
proached  in  the  operations  of  a  common  stove  or  range. 

The  costliness  of  electric  heat  forbids  the  housekeeper  from 
using  much  of  it.  Her  main  source  of  heat  must  long  continue 
to  be  the  common  fuels.  These,  however,  thanks  to  cheap  non- 
conductors, may  be  used  with  much  more  economy  and  comfort 

1  Rolla  C.  Carpenter,  "Heating  and  Ventilating  Buildings,"  p.  229.  New 
York,  John  Wiley  &  Sons,  1905.  * 


NORWEGIAN  COOKER 


189 


than  of  old.  Take,  for  example,  the  Norwegian  cooking  box, 
steadily  gaining  favor  in  Europe  and  well  worthy  of  popularity 
in  America.  It  consists  of  a  box,  preferably 
cubical,  made  of  closely  fitted  thick  boards, 
with  a  lid  which  fits  tightly.  Box  and  lid  are 
thickly  lined  with  felt  or  woolen  cloth,  and  filled  with  hay  except 
where  pots  are  placed.  These  pots,  filled  with  the  materials  for 
a  soup,  a  stew,  a  ragout,  are  brought  to  a  boil  on  a  fire  and  then 
placed  within  the  box,  its  lid  being  then  fastened  down.  For 
two  hours  or  so  the  cooking  process  goes  on  with  no  further 
application  of  heat.  To  be  sure  the  temperature  has  fallen  a  little, 
but  it  is  still  high  enough  to  complete  the  preparation  of  a  whole- 
some and  palatable  dish,  with  economy  of  fuel  and  labor,  without 
unduly  heating  the  kitchen. 


Norwegian  cooker. 


On  the  same  principle  is  the  Aladdin  oven,  invented  by  the  late 
Edward  Atkinson  of  Boston,  and  manufactured  by  the  Aladdin 


190     PROPERTIES-IMPRESSIBILITY 

Oven  Company,  Brookline,  Mass.    It  is  built  of  iron,  surrounded 
with  air  cell  asbestos  board,  so  as  to  maintain  a  cooking  tem- 
perature of  400°  Fahr.  with  little  fuel  or  atten- 
tion.    Its  drop  door  when  open  forms  a  shelf,      Aladdin  Oven, 
when  closed  it  is  fastened  by  a  brass  eccentric 

catch,  ensuring  tightness ;  its 
wooden  stand  has  an  iron 
top  to  hold  the  oven  firmly 
in  place.  This  apparatus 
cooks  a  wide  range  of  dishes 
admirably,  retaining  the  na- 
tural flavors  of  meats,  fish, 
vegetables  and  fruits  as  ordi- 
nary excessive  temperatures 
never  do.  Mr.  Atkinson 
wrote  "The  Science  of  Nutri- 
tion," which  sets  forth  the 
construction  and  uses  of  this 
oven.1 

Every,,  property  of  matter 
seems  universal.  The  best 
non-conductor  of  heat  trans- 
mits a  little  heat ;  the  best 
conductor  is  by  no  means  perfect:  the  two  classes  of  substances 
are  joined  by  materials  which  gradually  approach  one  end  of  the 
scale  or  the  other.  Nothing  is  so  hard  but  that 
it  may  be  indented  or  engraved,  and  where  Matter  Impressed 
neither  a  blow  nor  severe  pressure  is  employed,  by  Its  History, 
we  may  have,  as  in  the  photographic  plate,  an 
impression  which  is  chemical  instead  of  mechanical,  displaying 
itself  to  the  eye  only  when  treated  with  a  suitable  developer.  A 
bar  of  steel  hammered  on  an  anvil  is  changed  in  properties ;  as  it 
becomes  closer  in  texture  its  tenacity  is  increased.  When  that 
bar  takes  its  place  in  a  structure,  the  work  it  has  to  do,  the  shocks 
it  bears,  equally  tell  upon  its  fibres.  Stresses  and  strains  leave 
their  effects  upon  the  stoutest  machines,  engines,  bridges;  they 


Aladdin  oven. 


1  Published  by  Damrell  &  Upham,  Boston.     $1.00. 


RECURRENT  STRESSES  191 

are  never  the  same  afterward  as  before,  and  usually  their  ex- 
perience does  them  harm.  Says  an  eminent  engineer,  Mr.  W. 
Anderson  :  'The  constant  recurrence  of  stresses,  even  those  within 
the  elastic  limit,  causes  changes  in  the  arrangement  of  the  par- 
ticles which  slowly  alter  their  properties.  In  this  way  pieces  of 
machinery,  which  theoretically  were  abundantly  strong  for  the 
work  they  had  to  do,  have  after  a  time  failed.  The  effect  is  inten- 
sified if  the  stress  is  suddenly  applied,  as  in  the  case  of  armor 
plate,  or  in  the  wheels  of  a  locomotive.  .  .  .  When  considerable 
masses  of  metal  have  been  forged,  or  severely  pressed  while 
heated,  the  subsequent  cooling  of  the  mass  imposes  restrictions  on 
the  free  movement  of  some  if  not  all  the  particles,  hence  internal 
stresses  are  developed  which  slowly  assert  themselves  and  often 
cause  unexpected  failures.  In  the  manufacture  of  dies  for  coin- 
age, of  chilled  rollers,  of  shot  and  shell  hardened  in  an  unequal 
manner,  spontaneous  fractures  take  place  without  apparent  cause, 
through  constrained  molecular  motion  of  the  inner  particles 
gradually  extending  the  motion  of  the  outer  ones  until  a  break 
occurs." 

Sir  Benjamin  Baker  says:— "Many  engineers  ignore  the  fact 
that  a  bar  of  iron  may  be  broken  in  two  ways — by  a  single  appli- 
cation of  a  heavy  stress,  or  by  the  repeated  application  of  a  com- 
paratively light  stress.  An  athlete's  muscles  have  often  been 
likened  to  a  bar  of  iron,  but  if  'fatigue'  be  in  question,  the  simile 
is  very  wide  of  the  truth.  Intermittent  action,  the  alternative  pull 
and  thrust  of  the  rower,  or  of  the  laborer  turning  a  winch,  is  what 
the  muscle  likes  and  the  bar  abhors.  A  long  time  ago  Braith- 
waite  correctly  attributed  the  failure  of  girders,  carrying  a  large 
brewery  vat,  to  the  vessel  being  sometimes  full  and  sometimes 
empty,  the  repeated  deflection,  although  imperceptibly  slow  and 
free  from  vibration,  deteriorating  the  metal,  until  in  the  course 
of  years  it  broke.  These  girders  were  of  cast  iron,  but  it  was 
equally  well  known  that  wrought  iron  was  similarly  affected,  for 
Nasmyth  afterward  called  attention  to  the  fact  that  the  alternate 
strain  in  axles  rendered  them  weak  and  brittle,  and  suggested  an- 
nealing as  a  remedy,  having  found  that  an  axle  which  would  snap 
with  one  blow  when  worn,  would  bear  eighteen  blows  when  new 
or  just  after  annealing.  We  know  that  the  toughest  wire  ca^ 


192  PROPERTIES— MAGNETIC 

be  broken  if  bent  backward  and  forward  at  a  sharp  angle ;  perhaps 
only  to  locomotive  and  marine  engineers  does  it  appear  that  the 
same  result  will  follow  in  time  even  when  the  bending  is  so  slight 
as  to  be  unseen  by  the  eye.  A  locomotive  crank-axle  bends  but 
1/34  inch,  and  a  straight  driving  axle  but  1/64,  under  the  heaviest 
bending  stresses  to  wrhich  they  are  exposed,  and  yet  their  life  is 
limited.  Experience  proves  that  a  very  moderate  stress  alter- 
nating from  tension  to  compression,  if  repeated  about  a  hundred 
million  times,  will  cause  fracture  as  surely  as  bending  to  a  sharp 
angle  repeated  a  few  hundred  times." 

Hence  an  axle,  or  other  structure,  should  be  tested  by  just  such 
stresses  as  it  is  to  withstand  in  practice.  A  steel  bar  may  satis- 
factorily pass  a  tensile  test  applied  in  one  direction,  only  to  break 
down  disastrously  under  alternating  stresses  each  less  severe. 

That  matter  virtually  remembers  its  impressions  is  plain  when 
we  study  magnetism.  Steel  when  magnetized  for  the  first  time 
does  not  behave  as  when  magnetized  after- 
Magnetization,  ward.  It  is  as  if  magnetism  at  its  first  onset 
threw  aside  barriers  which  never  again  stood 
in  its  way.  If  the  steel  is  to  be  brought  to  its  original  state  it  must 
be  melted  and  recast,  or  raised  to  a  white  heat  for  a  long  time. 
In  quite  other  fields  of  channeled  motion  we  remark  that  violins 
take  on  a  richer  sonority  with  age ;  their  fibres,  under  the  player's 
hand,  seem  to  fall  into  such  lines  as  better  lend  themselves  to 
musical  expression. 

In  1878  the  late  Professor  Alfred  M.  Mayer  of  the  Stevens 
Institute  of  Technology,  Hoboken,  New  Jersey,  published  a  series 
of  remarkable  experiments  in  the  "American  Journal  of 
Science."  He  there  told  and  pictured  how  he  had  magnetized 
several  small  steel  needles,  thrust  through  bits  of  cork  set  afloat 
in  water,  the  south  pole  of  each  needle  being  upward.  As  the 
needles  repelled  each  other,  or  had  their  repulsion  somewhat  over- 
come by  a  large  magnet  held  above  them  with  its  north  pole 
downward,  the  needles  disposed  themselves  symmetrically  in 
outlines  of  great  interest,  which  varied,  of  course,  with  the  num- 
ber of  needles  afloat  at  any  one  time.  Three  needles  formed  an 
3quilateral  triangle,  four  made  up  a  square,  five  disposed  them- 
;elves  either  as  a  pentagon  or  as  a  square  with  one  magnet  at  its 


MAGNETIC  SYMMETRY 


193 


centre,  and  so  on  in  a  series  of  regular  combinations,  all  suggest- 
ing that  magnetic  forces  may  underlie  the  structure  of  crystals. 


Mayer's  floating  magnets. 

One  of  the  remarkable  attributes  of  a  crystal  is  its  ability  to 
grow  and  act  as  a  unit,  as  if  it  had  a  life  of  its  own,  despite  the 
evident  variety  and  great  number  of  its  parts. 

Take  a  crystal  of  alum,  break  off  a  corner  and        The  C78tal 
.  ,      .  .  Foreshadows  the 

then  immerse  tr°  broken  mass  in  its  mother  plant. 

liquor;  at  once  the  crystal  will  repair  itself, 
new  molecules  building  themselves  into  its  structure  as  if  they 
knew  where  to  go.  This  unity  of  effect  may  be  observed  during 
a  northern  winter  on  a  scale  much  more  striking.  In  cold 
weather  on  a  large  sheet  of  plate  glass  exposed  as  a  window,  a 
frost  pattern  will  extend  itself  as  if  a  tree,  beautiful  branches 


194        PROPERTIES— CRYSTALLINE 

spreading  themselves  from  a  main  stem  which  may  be  seven  feet 
in  height.  It  is  altogether  probable  that  polar  forces,  such  as  we 
observe  in  the  magnet,  are  here  at  work.  Their  harmony  of  effect, 


tsar 


A 

Alum  crystal. 


B 


After  a  part  has  Restored  by  im- 

been  broken  off.  mersion  in  alum 

solution. 

From  photographs  by  Herr  Hugo  Schmidt,  Hackley  School,  Tarry- 
town,  N.  Y. 

in  spaces  comparatively  vast,  is  astonishing.  Forces  of  allied  char- 
acter rise  to  a  plane  yet  higher  in  vegetation,  culminating  in  the 
magnificent  sequoia  of  California,  whose  life,  measured  by  thou- 
sands of  years,  goes  back  almost  to  the  dawn  of  human  civiliza- 
tion. The  union  of  tools,  levers,  wheels,  as  an  organized  machine ; 
the  co-ordination  in  research  of  the  parts  to  be  played  by  ob- 
servers, recorders,  depicters,  generalizers ;  the  regimentation  of 
soldiers,  so  that  all  march,  advance  and  fire  as  one  man  under 
the  control  of  a  single  will,  is  prefigured  in  the  forces  which  make 
a  unit  of  every  crystal  of  saltpetre  in  a  soldier's  cartridge- 
box.  Of  all  the  characteristics  of  matter  none  is  more  pervasive 
and  more  marvelous  than  its  ability  to  form  a  unit  which  moves 
and  acts  as  if  no  part  were  separable  from  any  other,  while  mani- 
festing a  highly  complicated  structure,  with  functions  at  once 
intricate  and  co-ordinate. 

Qualities  of  matter,  much  more  simple,  may  now  engage  our 

attention.    First,  then,  let  us  note  how  minute  influences,  acting 

for  long  stretches   of  time,  may  change  the 

During  Long        qualities    of   metals    and    rocks.     Forces,   too 

Periods  Minute        sli   ht    for   measurement   as   yet    are   known   in 

Influences  h  J 

Become  Telling.      tne  course  °*  a  vear  or  two  to  affect  steel  at 
times   favorably,  at  other  times  unfavorably. 


CHANGES  THROUGH  TIME 


195 


The  highest  grades  of  tool-steel  are  improved  by  being  kept  in 
stock  for  a  considerable  time,  the  longer  the  better.  It  seems 
that  bayonets,  swords,  and  guns  are  liable  to  changes  which  may 
account  for  failure  under  sudden  thrust  or  strain.  Gauges  of 
tool  steel,  which  are  required  to  be  hard  in  the  extreme,  are 
finished  to  their  standard  sizes  a  year  or  two  after  the  hardening 
process.  Slow  molecular  changes  register  themselves  in  altered 
dimensions.  In  the  Bureau  of  Standards  at  Washington  are  a 
yard  in  steel  and  a  yard  in  brass,  at  first  identical  in  length ;  after 
twenty  years  they  were  found  to  vary  by  the  1/5000  of  an  inch. 
Take  another  case,  familiar  enough  to  the  railroad  engineer:  in 
a  mine,  or  a  tunnel,  the  roof  or  wall  may  tumble  down  a  month 
or  more  after  a  blasting.  The  stone  which  fell  immediately  upon 
the  explosion  was  far  from  representing  all  the  work  done  by  the 
dynamite.  A  stress  was  set  up  in  large  areas  of  rock  and  this  at 
last,  beginning  in  slight  cracks,  overcame  the  cohesion  of  masses 
of  huge  extent. 

Properties  undergo  change  during  the  simple  flight  of  time:  a 
parallel  diversity  is  worthy  of  remark.  A  substance  exhibits 
quite  diverse  qualities  according  to  whether  the  action  upon  it  is 
slow  or  speedy.  A  paraffine  candle  protruding  horizontally  half 
way  out  of  a  box,  during  a  New  York  summer  will  at  last  point 
directly  downward,  for  all  its  brittleness.  If  shoemaker's  wax  is 
struck  a  sudden  blow,  it  breaks  into  bits  as  might  a  pane  of  win- 
dow glass.  But  place  leaden  balls  on  the  surface  of  this  same 
wax  and  in  the  course  of  ten  or  twelve  weeks  you  will  find  them 
sunk  to  the  bottom  of  the  mass.  When  sharply  smitten,  the  wax 


i 


Iron  tube  enclosing  marble  before 
and  after  deformation. 


Marble  before  deformation 
and  after. 


196          PROPERTIES-PLASTICITY 

is  rigid  and  brittle;  to  a  long  continued,  moderate  pressure  the 
wax  proves  plastic,  semi-fluid  almost.  All  this  is  repeated  when 
stone  is  subjected  to  severe  pressure  for  as  long  a  period  as  two 
months.  At  McGill  University,  Montreal,  a  small  cylinder  of 
marble  thus  treated  by  Professor  Frank  D.  Adams  became  of 
bulging  form,  without  fracture,  but  with  a  reduction  in  tensile 
strength  of  one-half.  When  the  pressure  was  applied  during  but 
ninety  minutes  the  tensile  strength  of  the  resulting  mass  was  but 
one-third  that  presented  by  the  original  marble ;  when  the  experi- 
ment occupied  but  ten  minutes  the  tenacity  fell  to  somewhat  less 
than  one-fourth  its  first  degree.  These  researches  shed  light  on 
the  stratifications  of  rocks  often  folded  under  extreme  pressure 
as  if  rubber  or  paste. 

Take  another  and  quite  different  example  of  how  variations  in 
time  bring  about  wide  contrasts  of  result :  a  rubber  ball  thrown  in 
play  at  a  wall  rebounds;  send  it  forth  from  a  cannon,  with  a 
hundred- fold  this  velocity,  and  it  pierces  the  wall  as  might  a  shot 
of  steel. 


CHAPTER  XV 
PROPERTIES-Con/m«<?rf.    RADIO-ACTIVITY 

Properties  most  evident  are  studied  first  .  .  .  Then  those  hidden  from 
cursory  view  .  .  .  Radio-activity  revealed  by  the  electrician  .  .  .  A 
property  which  may  be  universal  and  of  the  highest  import  ...  Its 
study  brings  us  near  to  ultimate  explanations  .  .  .  Faraday's  prophetic 
views. 

T)ROPERTIES  age  after  age  have  become  more  and  more  in- 
X  timately  known.  At  first  the  savage  took  account  solely  of 
the  obvious  strength  of  an  oak,  the  sharpness  of  a  flint,  the 
pliability  of  a  sinew.  With  the  first  kindling  of  fire  he  discovered 
a  new  round  of  properties  in  things  long  familiar.  All  kinds  of 
wood,  especially  when  dry,  were  found  combustible,  so  were  straw 
and  twigs,  as  well  as  the  fat  of  birds,  the  oil  of  fish.  Then  it  was 
noticed  that  the  ground  beneath  a  fire  remained  unburnt  and  grew 
firm  and  hard,  so  that  its  clay  or  mud  might  be  used  for  rude  fur- 
naces and  ovens.  Soon  come  experiments  as  to  the  coverings 
which  maintain  coals  at  red  heat,  ashes  proving  the  readiest  and 
best. 

A  century  ago  the  mastery  of  electricity  began  to  unfold  a  new 
knowledge  of  properties,  so  wide  and  intimate  as  to  recall  the 
immense  expansion  of  such  knowledge  that  long  before  had  fol- 
lowed upon  the  kindling  of  fire.  The  successors  of  Volta,  as 
they  reproduced  his  crown  of  cups,  asked,  What  metals  dissolved 
in  what  liquids  will  give  us  an  electric  current  at  least  outlay? 
Then  followed  the  further  question,  What  metals  drawn  into 
wire  will  bear  currents  afar  with  least  loss?  With  the  invention 
of  the  electro-magnet  came  another  query,  What  kinds  of  iron 
are  most  swiftly  and  largely  magnetized  by  a  current;  and  when 
the  current  ceases,  which  of  them  loses  its  magnetism  in  the 
shortest  time?  Plainly  enough  the  electrician  regards  copper, 
zinc,  iron,  steel,  acids,  alkalis  from  a  new  point  of  view;  he  dis- 

197 


198     PROPERTIES— RADIO-ACTIVITY 

covers  in  them  properties  which  until  his  advent  had  been  utterly 
ignored. 

Among  the  properties  of  matter  revealed  by  electricity  none 
are  more  striking  than  those  displayed  in  tubes  containing  highly 
rarified  gases.  The  study  of  their  phenomena  has  led  to  dis- 
coveries which  bring  us  within  view  of  an  ultimate  explanation 
of  properties,  an  understanding  of  how  matter  is  atomically  built. 
All  this  began  simply  enough  as  Plucker,  in  i859>  sen^  an  elec~ 
tric  discharge  through  a  tube  fairly  well  exhausted,  producing 
singular  bands  of  color.  Geissler,  afterward  using  tubes  more 
exhausted,  produced  bands  of  still  higher  variegation.  In  1875 
Professor  William  Crookes  devised  the  all  but  vacuous  tube 
which  bears  his  name,  through  which  he  sent  electric  pulses  from 
a  cathode  pole,  revealing  what  he  called  "radiant  matter,"  as 
borne  in  a  beam  of  cathode  rays,  as  much  more  tenuous  than 
ordinary  gases  as  these  are  more  rare  than  liquids.  In  1894 
Professor  Philipp  Lenard  observed  that  cathode  rays  passed 
through  a  thin  plate  of  aluminium,  much  as  daylight  takes  its 
way  through  a  film  of  translucent  marble.  Next  year  came  the 
epoch-making  discovery  of  Professor  Conrad  Wilhelm  Rontgen 
that  cathode  rays  consist  in  part  of  X-rays  which  readily  pass 
through  human  flesh,  so  as  to  cast  shadows  of  bones  upon  a 
photographic  plate.  Cathode  rays  make  air  a  fairly  good  con- 
ductor of  electricity,  while  ordinary  air  is  non-conducting  in  an 
extreme  degree.  This  singular  power  is  also  possessed  by  the 
ultra-violet  rays  of  sunshine,  as  readily  shown  by  an  electroscope. 
In  1897  Professor  Joseph  J.  Thomson,  of  Cambridge  University, 
demonstrated  that  cathode  rays  are  made  up  of  corpuscles,  or 
electrons,  about  one-thousandth  part  the  size  of  a  hydrogen  atom, 
and  bearing  a  charge  of  negative  electricity.  Such  electrons  form 
a  small  part  of  every  chemical  atom,  the  remainder  of  which  is, 
of  course,  positively  electrified.  All  electrons  are  alike,  however 
various  the  "elements"  whence  they  are  derived ;  as  the  most 
minute  masses  known  to  science  they  may  be  among  the  primal 
units  of  all  matter. 

France,  as  well  as  Germany  and  England,  was  to  take  a  leading 
part  in  furthering  the  study  of  radio-activity.  In  Paris  the  fa- 
mous Becquerel  family  had  for  three  generations  devoted  them- 


RADIUM  199 

selves  to  studying  phosphorescence.  Henri  Becquerel,  third  of 
the  line,  said,  "I  wonder  if  a  phosphorescent  substance,  such  as 
zinc  sulphide,  would  be  excited  by  X-rays."  He  tried  the  ex- 
periment, causing  the  sulphide  to  glow  with  new  vigor.  From 
that  moment  proofs  have  accumulated  that  the  rays  of  common 
phosphorescence  such  as  are  emitted  by  matches,  decaying  wood 
and  fish,  are  of  kin  to  the  cathode  rays  which  the  electrician 
evokes  from  any  substance  whatever  when  he  employs  a  high- 
tension  current.  One  day  M.  Becquerel  came  upon  a  remarkable 
discovery.  He  noticed  that  compounds  of  uranium,  whether 
phosphorescent  or  not,  affected  a  photographic  plate  through  an 
opaque  covering  of  black  paper,  and  rendered  the  adjacent  air  an 
electric  conductor.  Compounds  of  thorium,  similar  to  those  used 
for  incandescent  mantles,  were  found  to  have  the  same  proper- 
ties. And  here  was  detected  the  cause  of  an  annoyance  and  loss 
which  had  long  perplexed  photographers.  Often  they  had  be- 
stowed sensitive  paper  or  plates  within  wrappers  of  stout  paper, 
or  card,  or  thick  wood,  secluded  in  dark  cupboards  or  drawers. 
All  in  vain.  At  the  end  of  a  few  weeks  or  months  these  carefully 
guarded  surfaces  were  as  much  discolored  as  if  they  had  been  for 
a  few  minutes  exposed,  here  and  there,  to  daylight  itself.  All 
the.  while  each  material  relied  upon  as  a  safeguard  had  been 
sending  forth  a  feeble  but  constant  beam;  treachery  had  lurked 
in  the  trusted  guardian. 

At  the  suggestion  of  M.  Becquerel,  M.  and  Madame  Pierre 
Curie  undertook  a  thorough  quest  for  these  effects  in  a  wide 
diversity  of  substances.  They  found  that  several  minerals  con- 
taining uranium  were  more  radio-active  than  that  element  itself. 
Pitchblende,  for  instance,  consisting  mainly  of  an  oxide  of  ura- 
nium, was  especially  energetic  as  it  approached  an  electroscope, 
suggesting  the  presence  of  an  uncommonly  active  constituent, 
thus  far  not  identified.  At  the  end  of  a  most  laborious  series  of 
separations  they  came  at  last  to  a  minute  quantity  of  radium 
chloride  displaying  extraordinary  properties.  Another  compound 
of  radium,  a  bromide,  has  since  been  arrived  at :  radium  by  'itself 
has  not  yet  been  obtained.  In  radio-activity  radium  chloride  sur- 
passes uranium  about  one-million-fold.  Provided  with  an  electro- 
scope of  exquisite  sensibility,  Professor  Ernest  Rutherford  of 


200     PROPERTIES— RADIO-ACTIVITY 

McGill  University,  Montreal,  has  discovered  seven  distinct  radia- 
tions from  radium,  each  with  characteristics  of  its  own.  Directed 
upon  plates  of  aluminium  he  finds  its  gamma  rays  to  be  100 
times  more  penetrating  than  its  beta  rays,  and  beta  rays  100 
times  more  penetrating  than  its  alpha  rays.  Each  radiation  has 
qualities  as  distinct  as  those  of  an  ordinary  chemical  element. 
Beta  rays  behave  in  all  respects  like  cathode  rays,  so  that  here  a 
bridge  is  discerned  betwixt  the  qualities  of  radium  and  the  long 
familiar  phenomena  of  the  Crookes  tube. 

The  substance  ranking  next  in  radio-activity  to  radium  is 
thorium.  Professor  Rutherford  has  observed  it  throwing  off  a 
substance  he  calls  Thorium  X;  this  radiates  strongly  for  a  time, 
the  parent  mass  not  radiating  at  all.  Gradually  Thorium  X 
ceases  to  radiate  and  the  original  thorium  resumes  an  emission 
of  Thorium  X.  From  Thorium  X  emanates  what  seems  a  gas, 
condensible  by  extreme  cold,  which  attaches  itself  to  adjacent 
bodies  so  as  to  make  them  radio-active.  This  emanation  in  its 
turn  produces  successively  three  new  and  distinct  kinds  of  radia- 
tion. Professor  Charles  Baskerville,  of  the  College  of  the  City 
of  New  York,  has  separated  from  thorium  two  substances  prob- 
ably elementary,  carolinium  and  berzelium. 

Other  radio-active  substances  have  each  several  derivatives: 
actinium  has  nine,  uranium  has  four.  As  researchers  broaden 
their  range  of  inquiry  they  steadily  lengthen  the  list  of  radio- 
active substances.  Minerals  of  many  kinds,  water  from  springs, 
especially  those  of  medicinal  value,  the  leaves  of  plants,  newly 
fallen  snow,  and  even  common  air,  are  found  to  be  radio-active, 
although  usually  in  but  a  slight  degree,  so  that  the  doubt  mav  be 
expressed,  Is  the  observed  effect  due  to  a  trace  of  some  highly 
radio-active  material  diffused  in  something  else  which  is  not 
radio-active  at  all?  Should  it  be  established  that  radio-activity 
is  really  present  in  all  matter  it  would  be  no  other  than  a  parallel 
to  what,  at  another  point  in  the  physical  scale,  presents  itself  as 
ordinary  evaporation. 

In  a  northern  winter  we  may  observe  in  air  almost  still,  the 
wasting  away  of  a  large  block  of  ice,  so  that  during  a  week  it 
loses  a  considerable  part  of  its  bulk.  The  giving  forth  of  vapor 
is  evidently  not  restricted  to  high  or  to  ordinary  temperatures,  but 


SOLIDS  DIFFUSIBLE  201 

may  occur  below  the  freezing  point  of  water.  In  1863,  Thomas 
Graham,  the  eminent  Scottish  physicist,  from  many  experiments 
with  metals  expressed  the  opinion  that  what 
seems  to  be  a  solid  may  be  also  in  a  minute  Solids  are  not  as 
degree  both  liquid  and  gaseous  as  well.  Con- 
firmation of  this  view  was  afforded  in  1886 
by  Professor  W.  Spring,  of  Liege,  who  formed  alloys  by  strongly 
compressing  their  constituents  as  powders  at  ordinary  tempera- 
tures. It  is  probable  that  a  slight  pervasive  liquidity  gave  suc- 
cess to  the  experiment.  Professor  Roberts-Austen  once  observed 
that  an  electric-deposit  of  iron  on  a  clean  copper  plate  adhered  so 
firmly  that  when  they  were  severed  by  force,  a  film  was  stripped 
from  the  copper  plate  and  remained  on  the  iron,  signifying  that 
the  two  metals  had  penetrated  each  other  at  an  ordinary  tempera- 
ture. This  interpenetration  he  found  to  take  place  through  films 
of  electro-deposited  nickel.  In  a  remarkable  round  of  experi- 
ments he  also  found  that  at  100°  C,  a  temperature  much  below 
the  fusing  point  of  lead,  gold  as  leaf  is  slightly  diffused  through 
a  mass  of  lead;  when  the  lead  is  fluid  at  550°  C.,  the  proportion 
of  diffused  gold  is  increased  160,000  times.  This  volatility  of  the 
particles  of  a  heavy  metal  shows  us  plainly  that  virtual  evapora- 
tion may  be  always  taking  place  from  metallic  surfaces  at  ordi- 
nary temperatures,— a  phenomenon  which  may  be  the  same  in 
kind  as  the  pouring  out  of  a  perceptible  stream  of  corpuscles  un- 
der strong  electrical  excitation.  The  analogy  goes  further,  at 
least  in  the  case  of  liquids,  which  exhale  a  vapor  usually  different 
in  composition  from  the  parent  body ;  take,  for  example,  a  solu- 
tion of  sugar  in  water  which  sends  forth  watery  vapor  only,  or 
observe  a  mixture  of  much  water  and  a  little  alcohol  as  it  emits 
a  vapor  largely  alcoholic  and  but  slightly  aqueous. 

Here  we  are  reminded  of  a  striking  experiment  by  Faraday : 
exciting  an  electro-magnet  of  gigantic  proportions  he  showed 
that  every  substance  he  brought  near  to  it  was 
affected  in  a  definite  degree.    He  found  iron  to      Every  Property 
be  pre-eminently  magnetic,  much  as  Madame  May  be  Universal. 
Curie  has   shown   radium   to  be   vastly   more 
radio-active  than  any  other  substance.     From  Faraday's  time  to 
the  present  hour  the  whole  trend  of  investigation  has  built  up  the 


202     PROPERTIES— RADIO-ACTIVITY 

probability  that  every  known  property  in  some  degree  exists  in  all 
matter  whatever.  Copper  conducts  electricity  remarkably  well, 
and  gutta  percha  conducts  remarkably  ill;  but  gutta  percha  has 
some  little  conductivity,  or  thinner  sheets  of  it  than  those  now  used 
would  suffice  to  keep  within  an  ocean  cable  the  throbs  which  pass 
between  America  and  Europe.  In  radio-activity  many  substances 
may  be  as  low  in  the  scale  as  is  gutta  percha  in  the  list  of  electric 
conductors;  in  that  case  no  existing  means  of  detection  would 
make  the  property  manifest. 

While  radio-activity  may  be  a  universal  property  of  matter,  to 

be  disclosed  more  and  more  as  means  of  detection  are  refined  and 

Radium  Reveals     imProved,  radium  compounds  are  to-day  in  a 

Properties          class   quite   by   themselves.     Radium   bromide 

Unknown  Till  constantly  maintains  itself  at  a  temperature  of 
Now.  3°  to  5°  C.  higher  than  that  of  its  surround- 

ings, so  that  every  hour  it  could  boil  its  own  weight  .of  water.  Pro- 
fessor Rutherford  estimates  the  life  of  radium  as  1,800  years,  its 
emanations  in  breaking  up  through  their  successive  stages  emitting 
about  three  million  times  as  much  energy  as  is  given  out  by  the 
union  of  an  equal  volume  of  hydrogen  and  oxygen,  mixed  in  the 
proportions  which  form  water,  a  union  accompanied  by  more  heat 
than  that  evolved  in  any  other  chemical  change.  Whence  this 
amazing  stream  of  energy?  It  is  probable  that  each  radium  atom 
may  break  into  minute  parts,  or  corpuscles,  which,  moving  at  a 
velocity  of  120,000  miles  a  second  or  so,  collide  so  as  to  cause  the 
observed  heat. 

From  another  side  the  compounds  of  radium  bid  us  revise  the 
laws  of  chemical  change  as  taught  up  to  the  close  of  the  nineteenth 
century.  In  the  pores  of  many  radio-active  minerals  may  be  found 
that  remarkable  element,  helium,  first  detected  in  the  sun  by 
means  of  the  spectroscope,  then  afterward  discovered  in  the  pores 
of  cleveite,  a  mineral  unearthed  in  Norway.  Sir  William  Ramsay 
and  Mr.  Frederick  Soddy  have  found  helium  in  the  gases  evolved 
from  radium  chloride  kept  as  a  solid  for  some  months.  The  spec- 
trum of  helium  was  at  first  invisible ;  it  soon  appeared  and  steadily 
grew  more  intense  with  the  lapse  of  time.  "It  appears  not  un- 
likely," says  Professor  Rutherford,  "that'  many  of  the  so-called 
chemical  elements  may  prove  to  be  compounds  of  helium,  or,  in 


Photograph  by  Rice,  Montreal. 


PROFESSOR  ERNEST  RUTHERFORD, 
McGiLL  UNIVERSITY,  MONTREAL. 


NEW  INSIGHTS  203 

other  words,  that  the  helium  atom  is  one  of  the  secondary  units 
with  which  the  heavier  atoms  are  built  up."1 

Already  the  phenomena  of  radio-activity,  although  of  puzzling 
intricacy,  have  greatly  broadened  our  conceptions  of  matter. 
Where  we  were  wont  to  deem  it  of  simple  structure,  it  displays  a 
baffling  complexity,  as  indeed  has  long  been  suggested  in  so  highly 
diversified  a  spectrum  as  that  of  iron.  We  find  that  radiations 
from  an  "element"  may  consist  not  only  in  the  undulations  of  an 
ether,  but  also  in  an  emission  of  matter  as  real  as  the  projection 
of  steam  from  a  boiling  pot.  Newton  believed  sunshine  to  be  a 
stream  of  corpuscles :  he  was  wrong  with  respect  to  sunlight,  his 
conception  is  true  of  many  other  kinds  of  radiation.  Until  quite 
lately  we  looked  upon  atoms  as  indivisible  bodies ;  to-day  we  have 
learned  that  at  least  some  of  them  may  on  occasion  divide  into 
many  parts,  each  part  moving  with  a  speed  approaching  that  of 
light,  with  energy  far  exceeding  that  of  any  chemical  action  we 
know.  In  the  field  of  ray-transmission  our  knowledge  has  under- 
gone a  like  gain  in  width.  Twenty  years  ago  we  spoke  of  the 
opacity  of  lead,  the  transparency  of  flint  glass,  as  absolute  proper- 
ties. To-day  we  learn  that  given  its  accordant  ray  any  substance 
whatever  affords  that  ray  free  passage,  as  when  oak  an  inch  thick 
transmits  pulses  from  radium.  Yet  more:  ordinary  chemical 
changes  require  us  to  bring  one  substance  into  contact  with  an- 
other ;  usually  we  must  also  apply  heat  or  electricity  to  the  bodies 
thus  joined  ;  they  are  always  responsive  to  changes  of  temperature. 
Within  the  past  six  years  we  have  become  acquainted  with  changes 
incomparably  more  energetic  than  those  of  the  most  violent  chem- 
ical action ;  many  of  them  proceed  with  apparent  spontaneity  from 
a  substance  all  by  itself.  In  the  case  of  radium  neither  extreme 
cold  nor  extreme  heat  has  any  perceptible  effect  upon  the  radiant 
stream. 

One  of  the  results  of  investigation  in  radio-activity  is  that  it 
shows  the  alchemists  in  their  attempts  at  transmutation  to  have 
stood  on  solid  ground.  Says  Professor  Rutherford :  "There  can 
be  no  doubt  that  in  the  radio-elements  we  are  witnessing  the  spon- 
taneous transformation  of  matter,  and  that  the  different  products 

1  Ernest  Rutherford  "Radio-activity."  Second  edition.  New  York :  Mac- 
raillan  Co.;  Cambridge,  England,  University  Press,  1905. 


204     PROPERTIES— RADIO-ACTIVITY 

which  arise  mark  the  stages  or  halting  places  in  the  process  of 
transformation,  where  the  atoms  are  able  to  exist  for  a  short  time 
before  breaking  up  into  new  systems." 

Radio-activity  has  a  vivid  interest  far  beyond  the  laboratories  of 
chemists  and  physicians.  One  of  the  long  standing  puzzles  of 

geology  has  been  to  explain  why  the  tempera- 
History  of  the        &  f  %  . 

Universe  ture  °*  tne  earth  has  remained  fairly  constant 

Rewritten  in  the      ever  since  organic  life  made  its  appearance.    A 

Light  of  sister  problem  has  been  the  maintenance  by  the 

Radio-Activity.        sun  of   ks   yast  Qutput  of   heat  and   ^^   agg 

after  age,  with  little  or  no  diminution  of  intensity.  Professor 
Rutherford  and  Mr.  Soddy  believe  that  the  phenomena  of  radio- 
activity may  solve  both  these  problems :  an  element  like  helium 
may  furnish  a  store  of  energy  vastly  greater  than  that  of  ordinary 
chemical  action,  and  much  lengthen  the  cooling  process  due  to 
radiation  from  either  the  sun  or  the  earth. 

Radio-activity,  furthermore,  throws  new  light  upon  evolution 
regarded  in  its  broadest  aspects.  The  corpuscles  discovered  in 
1897  by  Professor  J.  J.  Thomson,  as  he  severed  atoms  in  pieces, 
are  all  alike  whatever  chemical  element  may  be  the  parent  body. 
Hence  it  is  argued  that  we  may  have  here  the  primal  units  of  all 
matter  whatever.  Sir  Norman  Lockyer  long  ago  pointed  out  that 
helium  and  hydrogen  predominate  in  the  hottest  stars,  while  in 
stars  less  hot  more  complex  types  of  matter  appear.  He  argues 
that  these  stars  as  they  successively  lose  heat  show  a  development 
of  what  chemists  call  elements.  His  views  are  parallel  with  the 
suggestion  that  in  the  radio-active  corpuscle  we  make  acquaintance 
with  an  ultimate  element  of  all  matter,  whether  observed  in  a 
laboratory  tube  or  in  the  squadrons  bright  of  the  midnight 
heavens.1 

The  phenomena  of  radio-activity  revive  interest  in  the  prophetic 
views  of  Michael  Faraday.  In  1816,  when  he  was  but  twenty-four 
years  of  age,  he  delivered  a  lecture  at  the  Royal  Institution  in 

1  Radio-activity  and  other  physical  phenomena  recently  discovered  are 
set  forth  in  "The  New  Knowledge,"  by  Professor  Robert  Kennedy  Duncan, 
published  by  A.  S.  Barnes  &  Co.,  New  York,  1905 ;  and  "The  Recent 
Development  of  Physical  Science,"  by  W.  C.  D.  Whetham,  published  by 
John  Murray,  London,  and  P.  Blakiston,  Son  &  Co.,  Phila.,  1906. 


FARADAY'S  FORECAST  205 

London  on  Radiant  Matter.    In  the  course  of  his  remarks  there 
occurs  this  passage:— 

"If  we  now  conceive  a  change  as  far  beyond  vaporization  as 
that  is  above  fluidity,  and  then  take  into  account  the  proportional 
increased  extent  of  alteration  as  the  changes 
arise,  we  shall  perhaps,  if  we  can  form  any          Faraday's 
conception    at    all,    not    fall    short    of    radiant    Prophetic  Views. 
matter;   and   as   in   the   last   conversion   many 
qualities  were  lost,  so  here  also  many  more  would  disappear. 

"It  was  the  opinion  of  Newton,  and  of  many  other  distinguished 
philosophers,  that  this  conversion  was  possible,  and  continually 
going  on  in  the  processes  of  nature,  and  they  found  that  the  idea 
would  bear  without  injury  the  applications  of  mathematical  rea- 
soning— as  regards  heat,  for  instance.  If  assumed,  we  must  also 
assume  the  simplicity  of  matter;  for  it  would  follow  that  all  the 
variety  of  substances  with  which  we  are  acquainted  could  be  con- 
verted into  one  of  three  kinds  of  radiant  matter,  which  again  may 
differ  from  each  other  only  in  the  size  of  their  particles  or  their 
form.  The  properties  of  known  bodies  would  then  be  supposed 
to  arise  from  the  varied  arrangements  of  their  ultimate  atoms,  and 
belong  to  substances  only  as  long  as  their  compound  nature 
existed ;  and  thus  variety  of  matter  and  variety  of  properties 
would  be  found  co-essential."1 

Three  years  later  he  returned  to  this  theme  in  another 
lecture  :— 

"By  the  power  of  heat  all  solid  bodies  have  been  fused  into 
fluids,  and  there  are  very  few  the  conversion  of  which  into 
gaseous  forms  is  at  all  doubtful.  In  inverting  the  method,  at- 
tempts have  not  been  so  successful.  Many  gases  refuse  to  resign 
their  form,  and  some  fluids  have  not  been  frozen.  If,  however, 
we  adopt  means  which  depend  on  the  rearrangement  of  particles, 
then  these  refractory  instances  disappear,  and  by  combining  sub- 
stances together  we  can  make  them  take  the  solid,  fluid,  or 
gaseous  form  at  pleasure. 

"In  these  observations  on  the  changes  of  state,  I  have  purposely 
avoided  mentioning  the  radiant  state  of  matter,  being  purely 

1  "Life  and  Letters  of   Faraday,"  by  Bence  Jones.    Vol.  I,  p.  216. 


206     PROPERTIES— RADIO-ACTIVITY 

hypothetical,  it  would  not  have  been  just  to  the  demonstrated 
parts  of  the  science  to  weaken  the  force  of  their  laws  by  con- 
necting them  with  what  is  undecided.  I  may  now,  however, 
notice  a  progression  in  physical  properties  accompanying 
changes  of  form,  and  which  is  perhaps  sufficient  to  induce,  in 
the  inventive  and  sanguine  philosopher,  a  considerable  belief  in 
the  association  of  the  radiant  form  with  the  others  in  the  set 
of  changes  I  have  mentioned. 

"As  we  ascend  from  the  solid  to  the  fluid  and  gaseous  states, 
physical  properties  diminish  in  number  and  variety,  each  state 
having  some  of  those  which  belong  to  the  preceding  state.  When 
solids  are  converted  into  fluids,  all  varieties  of  hardness  and  soft- 
ness are  necessarily  lost.  Crystalline  and  other  shapes  are  de- 
stroyed. Opacity  and  color  frequently  give  way  to  a  colorless 
transparency,  and  a  general  mobility  of  particles  is  conferred. 

"Passing  onward  to  the  gaseous  state,  still  more  of  the  evident 
characters  of  bodies  are  annihilated.  The  immense  differences 
in  their  weights  almost  disappear;  the  remains  of  difference  in 
color  that  were  left,  are  lost.  Transparency  becomes  universal, 
and  they  are  all  elastic.  They  now  form  but  one  set  of  sub- 
stances, and  the  varieties  of  density,  hardness,  opacity,  color, 
elasticity  and  form,  which  render  the  number  of  solids  and  fluids 
almost  infinite,  are  now  supplied  by  a  few  slight  variations  in 
weight,  and  some  unimportant  shades  of  color. 

"To  those,  therefore,  who  admit  the  radiant  form  of  matter, 
no  difficulty  exists  in  the  simplicity  of  the  properties  it  possesses, 
but  rather  an  argument  in  their  favor.  These  persons  show  you 
a  gradual  resignation  of  properties  in  the  matter  we  can  appre- 
ciate as  the  matter  ascends  in  the  scale  of  forms,  and  they  would 
be  surprised  if  that  effect  were  to  cease  at  the  gaseous  state.  They 
point  out  the  greater  exertions  which  nature  makes  at  each  step 
of  the  change,  and  think  that,  consistently,  it  ought  to  be  greatest 
at  the  passage  from  the  gaseous  to  the  radiant  form."1 

This  remarkable  deliverance  recalls  what  another  great  ex- 
perimental philosopher,  Count  Rumford,  deduced  as  by  dint  of 
mechanical  motion  he  melted  ice  in  a  closed  and  insulated  re- 

1  "Life  and  Letters  of  Faraday,"  by  Bence  Jones.    Vol.  I,  p.  307. 


CAUSES  OF  PROPERTIES  207 

ceiver.  He  inferred  that  the  heat  thus  generated  was  not  a 
material  substance,  as  then  generally  supposed,  but  must  be  in 
essence  motion,  for  only  motion  had  brought  it  into  existence. 
As  we  follow  Faraday's  recital  of  the  successive  changes  in  prop- 
erties which  follow  upon  additions  of  heat,  in  other  words,  of 
mechanical  motion,  the  inference  is  irresistible  that  properties 
consist  in  the  distinct  motions  of  masses  of  definite  form  and 
size,  these  very  motions,  perhaps,  deciding  both  the  form  and 
size  of  each  mass. 


CHAPTER  XVI 
MEASUREMENT 

Methods  beginning  in  rule-of-thumb  proceed  to  the  utmost  refinement  .  .  . 
The  foot  and  cubit  .  .  .  The  metric  system  .  .  .  Refined  measurement  a 
means  of  discovery  .  .  .  The  interferometer  measures  1-5,000,000  inch 
...  A  light-wave  as  an  unvarying  unit  of  length. 

A  CHILD  notices  that  his  bedroom  is  smaller  than  the  family 
ZJL  parlor,  that  to-day  is  warmer  than  yesterday  was,  that  iron 
is  much  heavier  than  wood  and  less  easily  marked  by  a  blow. 
The  child  becomes  a  well  grown  boy  before  he  paces  the  length 
and  breadth  of  rooms  so  as  to  compare  their  areas  and  add  to  his 
mensuration  lesson  an  example  from  home.  If  instead  of  pacing 
he  were  to  use  a  foot-rule,  or  a  tape-line,  so  much  the  better. 
About  this  time  he  may  begin  to  observe  the  thermometer,  noting 
that  within  five  hours,  let  us  say,  it  has  fallen  eight  degrees.  As 
a  child  he  took  account  of  bigness  or  smallness,  lightness  or 
heaviness,  warmth  or  cold ;  now  he  passes  to  measuring  their 
amount.  In  so  doing  he  spans  in  a  few  years  what  has  required 
for  mankind  ages  of  history.  When  corn  and  peltries  are  bar- 
tered, or  axes  and  calumets  are  bought  and  sold,  a  shrewd  guess 
at  sizes  and  weights  is  enough  for  the  parties  to  the  bargain.  But 
when  gold  or  gems  change  owners  a  balance  of  delicacy  must  be 
set  up,  and  the  moral  code  resounds  with  imprecations  on  all  who 
tamper  with  its  weights  or  beam.  Perhaps  the  balance  was  sug- 
gested by  the  children's  teeter,  that  primitive  means  of  sport 
which  crosses  one  prone  tree  with  another,  playmates  rising  and 
falling  at  the  ends  of  the  upper,  moving  trunk.  In  essence  the 
most  refined  balance  of  to-day  is  a  teeter  still.  Its  successive 
improvements  register  the  transition  from  merely  considering 
what  a  thing  is,  whether  stone,  wood,  oil  or  what  not,  to  ascer- 
taining just  how  much  there  is  of  it ;  or,  in  formal  phrase,  to 
make  and  use  an  accurate  balance  means  passing  from  the  quali- 

208 


STANDARDS  OF  LENGTH  209 

tative  to  the  quantitative  stage  of  inquiry.  Before  Lavoisier's 
day  it  was  thought  that  any  part  of  a  substance  which  disappeared 
in  burning  was  annihilated.  Lavoisier  carefully  gathered  all  the 
products  of  combustion,  and  with  scales  of  precision  showed  that 
they  weighed  just  as  much  as  the  elements  before  they  were 
burned.  He  thus  laid  the  corner-stone  of  modern  chemistry  by 
demonstrating  that  matter  is  invariable  in  its  total  quantity,  not- 
withstanding all  chemical  unions  or  partings.  Phases  of  energy 
other  than  gravity  are  now  measured  with  instruments  as  much 
improved  of  late  years  as  the  balance ;  they  tell  us  the  great  truth 
that  energy  like  matter  is  constant  in  quantity,  however  much  it 
may  vary  from  form  to  form,  however  many  the  subtle  and 
elusive  disguises  it  may  wear. 

How  the  foot,  our  commonest  measure,  has  descended  to  us  is 
an  interesting  story.     The  oldest  known  standard  of  length,  the 
cubit,  was  the  distance  between  the  point  of  a 
man's  elbow  and  the  tip  of  his  middle  finger.      Foot  and  Cubit. 
In  Egypt  the  ordinary  cubit  was  18.24  inches, 
and  the  royal  cubit,  20.67  inches.     A  royal  cubit  in  hard  wood, 
perfectly  preserved,  was  discovered  among  the  ruins  of  Memphis 
early  in  the  nineteenth  century.     It  bears  the  date  of  the  reign 
of  Horus,  who  is  believed  to  have  become  King  of  Egypt  about 
1657  B.  C.    The  Greeks  adopted  a  foot,  equal  to  two-thirds  of  the 
ordinary  Egyptian  cubit,  as  their  standard  of  length.    This  meas- 
ure, 1 2. 1 6  inches,  was  introduced  into  Italy,  where  it  was  divided 
into  twelfths  or  inches  according  to  the  Roman  duodecimal  sys- 
tem, thence  to  find  its  way  throughout  Europe. 

Units  equally  important  with  the  cubit  were  from  of  old 
derived  from  the  finger  and  the  fingers  joined.  The  breadth  of 
the  forefinger  at  the  middle  part  cf  its  first  joint  became  the 
digit;  four  digits  were  taken  as  a  palm,  or  hand-breadth,  used  to 
this  day  in  measuring  horses.  Another  ancient  unit,  not  yet  ob- 
solete, the  pace,  is  forty  digits ;  while  the  fathom,  still  employed, 
is  ninety-six  digits,  as  spaced  by  the  extended  arms  from  the 
finger  tips.  The  cubit  is  twenty-four  digits,  and  the  foot  is  six- 
teen digits.  Thus  centuries  ago  were  laid  the  foundations  of  the 
measurement  of  space  as  an  art.  A  definite  part  of  the  human 
body  was  adopted  as  a  standard  of  length,  and  copied  on  rods 


210  MEASUREMENT 

of  wood  and  slabs  of  stone.  Divisors  and  multiples,  in  whole 
numbers,  were  derived  from  that  standard  for  convenience  in 
measuring  lines  comparatively  long  or  short.  And  yet  in  prac- 
tice, even  as  late  as  a  century  ago,  much  remained  faulty.  Stand- 
ards varied  from  nation  to  nation,  and  from  district  to  district. 
Carelessness  in  copying  yard-measures,  the  wear  and  tear  suf- 
fered by  lengths  of  wood  or  metal,  the  neglect  to  take  into  ac- 
count perturbing  effects  of  varying  temperatures  on  the  materials 
employed,  all  constrained  men  of  science  to  seek  a  standard  of 
measurement  upon  which  the  civilized  world  could  unite,  and 
which  might  be  safeguarded  against  inaccuracy. 

Here  the  Government  of  France  took  the  lead;  in  1791  it  ap- 
pointed as  a  committee  Lagrange,  Laplace,  Borda,  Monge,  and 
Condorcet,    five    illustrious    members    of    the 

The  Metric          French  Academy,  to  choose  a  natural  constant 
System.  •".  .         , 

from  which  a  unit  of  measurement  might  be 

derived,  that  constant  to  serve  for  comparison  or  reference  at 
need.  They  chose  the  world  itself  to  yield  the  unit  sought,  and 
set  on  foot  an  expedition  to  ascertain  the  length  of  a  quadrant, 
or  quarter-circle  of  the  earth,  from  the  equator  to  the  north  pole, 
taking  an  arc  of  the  meridian  from  Dunkirk  to  Barcelona,  nearly 
nine  and  one-half  degrees,  as  part  of  the  required  curve.  When 
the  quadrant  had  been  measured,  with  absolute  precision,  as  it 
was  believed,  its  ten-millionth  part,  the  metre,  was  adopted  as 
the  new  standard  of  length.  As  the  science  and  art  of  measure- 
ment have  since  advanced,  it  has  been  found  that  the  measured 
quadrant  is  about  1472.5  metres  longer  than  as  reported  in  1799 
by  the  commissioners.  Furthermore,  the  form  of  the  earth  is 
now  known  to  be  by  no  means  the  same  when  one  quadrant  is 
compared  with  another;  and  even  a  specific  quadrant  may  vary 
from  age  to  age  both  in  contour  and  length  as  the  planet  shrinks 
in  cooling,  becomes  abraded  by  wind  and  rain,  rises  or  falls  with 
earthquakes,  or  bends  under  mountains  of  ice  and  snow  in  its 
polar  zones.  All  this  has  led  to  the  judicious  conclusion  that  there 
is  no  advantage  in  adopting  a  quadrant  instead  of  a  conventional 
unit,  such  as  a  particular  rod  of  metal,  preserved  as  a  standard 
for  comparison  in  the  custody  of  authorities  national  or  inter- 
national. 


METRIC  SYSTEM  211 

What  gives  the  metric  system  pre-eminence  is  the  simplicity 
and  uniformity  of  its  decimal  scale,  forming  part  and  parcel  as 
it  does  of  the  decimal  system  of  notation,  and  lending  itself  to  a 
decimal  coinage  as  in  France,  Germany,  Italy,  and  Spain.  The 
metre  is  organically  related  to  all  measures  of  length,  surface, 
capacity,  solidity,  and  weight.  A  cubic  centimetre  of  water, 
taken  as  it  melts  in  a  vacuum,  at  4°  C,  the  temperature  of  maxi- 
mum density,  is  the  gram  from  which  other  weights  are  derived ; 
this  gram  of  water  becomes  a  measure  of  capacity,  the  millilitre, 
duly  linked  with  other  similar  measures.  Surfaces  are  measured 
in  square  metres,  solids  in  cubic  metres.  Simple  prefixes  are : 
deci— ,  one-tenth;  centi— ,  one-hundredth;  milli — ,  one-thou- 
sandth; deka— ,  multiplies  a  unit  by  ten;  hecto— ,  by  one  hun- 
dred; kilo—,  by  one  thousand;  and  myria— ,  by  ten  thousand. 

As  long  ago  as  1660  Mouton,  a  Jesuit  teacher  of  Lyons,  pro- 
posed a  metric  system  which  should  be  unalterable  because  de- 
rived from  the  globe  itself.  Watt,  the  great  improver  of  the 
steam  engine,  in  a  letter  of  November  I4th,  1783,  suggested  a 
metric  system  in  all  respects  such  as  the  French  commissioners 
eight  years  later  decided  to  adopt. 

The  nautical  mile  of  2029  yards  has  the  honor  of  being  the 
first  standard  based  upon  the  dimensions  of  the  globe.  It  was 
supposed  to  measure  one-sixtieth  part  of  a  degree  on  the  equa- 
tor; the  supposition  was  somewhat  in  error. 

Lord  Kelvin,  a  master  in  the  art  of  measurement,  an  inventor 
of  electrical  measuring  instruments  of  the  highest  precision,  as 
president  of   the   British  Association   for  the 
Advancement  of  Science  in  1871,  said :  "Ac-     uses  of  Refined 
curate  and  minute  measurement  seems  to  the       Measurement, 
non-scientific    imagination,    a    less    lofty    and 
dignified  work  than  looking  for  something  new.     But  nearly  all 
the  grandest  discoveries  of  science  have  been  but  the  rewards  of 
accurate  measurement  and  patient,  long-continued  labor  in  the 
minute  sifting  of  numerical  results.    The  popular  idea  of  New- 
ton's grand  discovery  is  that  the  theory  of  gravitation  flashed 
upon  his  mind,  and  so  the  discovery  was  made.    It  was  by  a  long 
train  of  mathematical  calculation,   founded  on  results  accumu- 
lated through  prodigious  toil  of  practical  astronomers,  that  New- 


212  MEASUREMENT 

ton  first  demonstrated  the  forces  urging  the  planets  towards  the 
sun,  determined  the  magnitude  of  those  forces,  and  discovered 
that  a  force  following  the  same  law  of  variation  with  distance 
urges  the  moon  towards  the  earth.  Then  first,  we  may  suppose, 
came  to  him  the  idea  of  the  universality  of  gravitation;  but  when 
he  attempted  to  compare  the  magnitude  of  the  force  on  the  moon 
with  the  magnitude  of  the  force  of  gravitation  of  a  heavy  body 
of  equal  mass  at  the  earth's  surface,  he  did  not  find  the  agreement 
which  the  law  he  was  discovering  required.  Not  for  years  after 
would  he  publish  his  discovery  as  made.  It  is  recounted  that, 
being  present  at  a  meeting  of  the  Royal  Society,  he  heard  a 
paper  read,  describing  a  geodesic  measurement  by  Picard,  which 
led  to  a  serious  correction  of  the  previously  accepted  estimate  of 
the  earth's  radius.  This  was  what  Newton  required ;  he  went 
home  with  the  result,  and  commenced  his  calculations,  but  felt 
so  much  agitated  that  he  handed  over  the  arithmetical  work  to  a 
friend;  then  (and  not  when  sitting  in  a  garden  he  saw  an  apple 
fall)  did  he  ascertain  that  gravitation  keeps  the  moon  in  her  orbit. 

"Faraday's  discovery  of  specific  inductive  capacity,  which  in- 
augurated the  new  philosophy,  tending  to  discard  action  at  a  dis- 
tance, was  the  result  of  minute  and  accurate  measurement  of 
electric  forces. 

"Joule's  discovery  of  a  thermo-dynamic  law,  through  the 
regions  of  electro-chemistry,  electro-magnetism,  and  elasticity  of 
gases  was  based  on  a  delicacy  of  thermometry  which  seemed  im- 
possible to  some  of  the  most  distinguished  chemists  of  the  day. 

"Andrews'  discovery  of  the  continuity  between  the  gaseous 
and  the  liquid  states  was  worked  out  by  many  years  of  laborious 
and  minute  measurement  of  phenomena  scarcely  sensible  to  the 
naked  eye." 

It  is  with  these  examples  before  them  that  investigators  take 

the  trouble  to  weigh  a  mass  in  a  vacuum,  to  watch  the  index  of 

a  balance  through  a  telescope  at  a  distance  of 

Further  twelve  feet,  or  use  an  interferometer  to  space 

Re^nT!ntS         o«t  an  inch  into  a  million  parts.     Their  one 
Needed.  .  t 

desire  is  to  arrive  at  truth  as  nearly  as  they 

can,  to  bring  grounds  of  disagreement  to  the  vanishing  point, 


THE  ARGON  GROUP  213 

and  ensure  exactness  in  all  the  computations  based  on  their 
work.  As  art  advances  from  plane  to  plane  it  demands  new 
niceties  of  measurement,  discovers  sources  of  error  unsuspected 
before,  and  avoids  these  errors  by  ingenious  precautions.  To- 
day observers  earnestly  wish  for  means  of  measurement  surpass- 
ing those  at  hand.  Take  the  astronomer  for  example.  One 
would  suppose  that  the  two  points  of  the  earth's  orbit  which  are 
farthest  apart,  divided  as  they  are  by  about  185,000,000  miles, 
would  afford  sufficient  room  between  them  for  a  base-line  where- 
with to  measure  celestial  spaces.  But  the  fact  is  otherwise.  So 
remote  are  the  fixed  stars  that  nearly  all  of  them  seem  unchanged 
in  place  whether  we  observe  them  on  January  3  or  July  3,  al- 
though meanwhile  we  have  changed  our  point  of  view  by  the 
whole  length  of  the  ellipse  described  by  the  earth  in  its  motion. 

Then,  too,  the  chemist  is  now  concerned  with  analyses  of  a 
delicacy  out  of  the  question  a  century  ago.  His  reward  is  in  dis- 
covering the  great  influence  wrought  bv  admixtures  so  slight  in 
amount  as  almost  to  defy  quantitative  recognition.  In  the  ex- 
periments by  M.  Guillaume,  elsewhere  recited,  his  unit  .through- 
out every  research  was  one-thousandth  of  a  millimetre,  or 
1/25,400  inch.  Argon,  a  gas  about  one-fourth  heavier  than 
oxygen,  forms  nearly  one-hundredth  part  of  the  atmosphere,  and 
yet  its  discovery  by  Lord  Rayleigh  dates  only  from  1894.  His 
feat  depended  not  only  upon  refined  modes  of  measurement,  but 
also  upon  his  challenging  the  traditional  analyses  of  common  air. 
The  utmost  resources  of  refrigeration,  of  spectroscopy,  and  of 
measurement  were  required  to  detect  four  elements  associated  in 
minute  quantities  with  argon,  and  of  like  chemical  inertness. 
These  are  helium,  having  a  density  of  1.98  as  compared  with  16 
for  oxygen ;  neon,  of  9.96  density ;  krypton,  of  40.78 ;  and  xenon, 
of  64.  Argon  itself  has  a  density  of  19.96.  "Air  contains,"  says 
Sir  William  Ramsay,  "one  or  two  parts  of  neon  per  100,000,  one 
or  two  parts  of  helium  per  1,000,000,  about  one  part  of  krypton 
per  1,000,000,  and  about  one  part  of  xenon  per  20,000,000;  these 
together  with  argon  form  no  less  than  0.937  per  cent,  of  the  atmo- 
sphere. As  a  group  these  elements  occupy  a  place  between  the 
strongly  electro-negative  elements  of  the  fluorine  group,  and  the 


214  MEASUREMENT 

very  positive  electro-positive  elements  of  the  lithium  group.  By 
virtue  of  their  lack  of  electric  polarity  and  their  inactivity  they 
form,  in  a  certain  sense,  a.  connecting  link  between  the  two."1 

As  measurements  become  more  and  more  precise  they  afford 

an  important  means  of  discovery.     Sir  William  Crookes  tells 

us : — "It  is  well  known  that  of  late  years  new 

Precise  Measure-  eiementary  bodies,  new  interesting  compounds 
ment  as  a  Means  ,  f  '  ,  ,.  1  .  .  t  .  , 

of  Discovery  ^ave  °*ten  been  discovered  in  residual  prod- 
ucts, in  slags,  flue-dusts,  and  waste  of  various 
kinds.  In  like  manner,  if  we  carefully  scrutinize  the  processes 
either  of  the  laboratory  or  of  nature,  we  may  occasionally  detect 
some  slight  anomaly,  some  unanticipated  phenomenon  which  we 
cannot  account  for,  and  which,  were  received  theories  correct  and 
sufficient,  ought  not  to  occur.  Such  residual  phenomena  are 
hints  which  may  lead  the  man  of  disciplined  mind  and  of  finished 
manipulative  skill  to  the  discovery  of  new  elements,  of  new 
laws,  possibly  even  of  new  forces ;  upon  undrilled  men  these  pos- 
sibilities are  simply  thrown  away.  The  untrained  physicist  or 
chemist  fails  to  catch  these  suggestive  glimpses.  If  they  appear 
under  his. hands,  he  ignores  them  as  the  miners  of  old  did  the 
ores  of  cobalt  and  nickel."2 

It  was  a  residual  effect  which  led  to  the  discovery  of  the  planet 
Neptune.  The  orbit  of  Uranus  being  exactly  defined,  it  was  noticed 
by  Adams  and  Leverrier  that  after  making  due  allowance  for  per- 
turbations by  all  known  bodies,  there  remained  a  small  disturbance 
which  they  believed  could  be  accounted  for  only  by  the  existence 
of  a  planet  as  yet  unobserved.  That  planet  was  forthwith  sought, 
and  soon  afterward  discovered,  proving  in  mass  and  path  to  be 
capable  of  just  the  effect  which  had  required  explanation. 

In  the  measurement  of  length  or  motion  a  most  refined  in- 
strument is  the  interferometer,  devised  by  Professor  A.  A.  Michel- 
son,  of  the  University  of  Chicago.  It  enables 

Measurements       an  observer  to  detect  a  movement  through  one 

Refined:  the  ., 

Interferometer.       five-millionth   of   an  inch.      The   principle   in- 
volved is  illustrated  in  a  simple  experiment.   If 

1  "Gases  of  the  Atmosphere:  History  of  Their  Discovery."    Third  edi- 
tion, with  portraits.    London  and  New  York,  Macmillan,  1906. 
'Nineteenth  Century  Magazine,  London,  July  1877. 


Photograph  by  Cox,  Chicago. 

PROFESSOR  A.  A.  MICHELSON, 
UNIVERSITY  OF  CHICAGO. 


OF  THE 

UNIVERSITY 


THE  INTERFEROMETER  215 

by  dropping  a  pebble  at  each  of  two  centres,  say  a  yard  apart,  in 
a  still  pond,  we  send  out  two  systems  of  waves,  each  system  will 
ripple  out  in  a  series  of  concentric  circles.  If,  when  the  waves 
meet,  the  crests  from  one  set  of  waves  coincide  with  the  depres- 


|-w   M 
I 


Michelson  interferometer. 

sions  from  the  other  set,  the  water  in  that  particular  spot  becomes 
smooth  because  one  set  of  waves  destroys  the  other.  In  this 
case  we  may  say  that  the  waves  interfere.  If,  on  the  other  hand, 
the  crests  of  waves  from  two  sources  should  coincide,  they  would 
rise  to  twice  their  original  height.  Light-waves  sent  out  in  a 
similar  mode  from  two  points  may  in  like  mariner  either  inter- 
fere, and  produce  darkness,  or  unite  to  produce  light  of  double 
brilliancy.  These  alternate  dark  and  bright  bands  are  called  in- 
terference fringes.  When  one  of  the  two  sources  of  light  is 
moved  through  a  very  small  space,  the  interference  fringes  at  a 
distance  move  through  a  space  so  much  larger  as  to  be  easily  ob- 
served and  measured,  enabling  an  observer  to  compute  the  short 
path  through  which  a  light-source  has  moved.  In  the  simplest 


216  MEASUREMENT 

form  of  interferometer,  light  from  any  chosen  source,  S,  is  ren- 
dered approximately  parallel  in  its  rays  by  a  double  convex  lens 
at  L.  The  light  falling  upon  the  glass  plate  A  is  divided  into  two 
beams,  one  of  which  passes  to  the  mirror  M,  while  the  other  is 
reflected  to  M1.  The  rays  reflected  from  M1,  which  pass  through 
A,  and  those  returned  from  M  reflected  at  d,  are  reunited,  and 
may  be  observed  at  E.  In  order  to  produce  optical  symmetry  of 
the  two  luminous  paths,  a  plate  C  exactly  like  A  is  introduced 
between  A  and  M.  When  the  distance  from  d  to  M  and  to  M1 
are  the  same  the  observer  sees  with  white  light  a  central  black 
spot  surrounded  with  colored  rings.  When  the  mirror  M1  is 
moved  parallel  to  itself  either  further  from  or  nearer  to  A,  the 
fringes  of  interference  move  across  the  field  of  view  at  E.  A 
displacement  of  one  fringe  corresponds  to  a  movement  of  half  a 
wave-length  of  light  by  the  mirror  M1.  By  counting  the  number 
of  fringes  corresponding  to  a  motion  of  M1  we  are  able  to  express 
the  displacement  in  terms  of  a  wave-length  of  light.  Where  by 
other  means  this  distance  is  measurable,  the  length  of  the  light- 
wave may  be  deduced.  With  intense  light  from  a  mercury  tube 
790,000  fringes  have  been  counted,  amounting  to  a  difference  in 
path  of  about  one- fourth  of  a  metre. 

Many  diverse  applications  of  the  interferometer  have  been  de- 
veloped, as,  for  example,  in  thermometry.  The  warmth  of  a 
hand  held  near  a  pencil  of  light  is  enough  to  cause  a  wavering  of 
the  fringes.  A  lighted  match  shows  contortions  as  here  illus- 
trated. When  the  air  is  heated  its 
density  and  refractive  power  diminish: 
it  follows  that  if  this  experiment  is 
tried  under  conditions  which  show  a 
regular  and  measurable  displacement  of 
^ie  f"n£es>  their  movement  will  in- 
dicate the  temperature  of  the  air.  This 

Light-wave  distorted™'         method  has  been   aPPlied   to  ascertain 
passing  through  very  high  temperatures,  such  as  those 

heated  air.  of  the  blast  furnace.     Most  metals  ex- 

pand one  or  two  parts  in  100,000  for  a  rise  in  temperature  of  one 
degree  centigrade.  When  a  small  specimen  is  examined  the 
whole  change  to  be  measured  may  be  only  about  I/ 10,000  inch,  a 


AN  UNVARYING  UNIT  217 

space  requiring  a  good  microscope  to  perceive,  but  readily  meas- 
ured by  an  interferometer.  It  means  a  displacement  amounting  to 
several  fringes,  and  this  may  be  measured  to  within  1/50  of  a 
fringe  or  less;  so  that  the  whole  displacement  may  be  measured 
to  within  a  fraction  of  one  per  cent.  Of  course,  with  long  bars 
the  accuracy  attainable  is  much  greater. 

The  interferometer  has  much  refined  the  indications  of  the 
balance.  In  a  noteworthy  experiment  Professor  Michelson  found 
the  amount  of  attraction  which  a  sphere  of  lead 
exerted  on  a  small  sphere  hung  on  an  arm  of 
a  delicate  balance.  The  amount  of  this  attrac- 
tion when  two  such  spheres  touch  is  proportional  to  the  diameter 
of  the  large  sphere,  which  in  this  case  was  about  eight  inches. 
The  attraction  on  the  small  ball  on  the  end  of  the  balance  was 
thus  the  same  fraction  of  its  weight  as  the  diameter  of  the  large 
ball  was  of  the  diameter  of  the  earth,— something  like  one 
twenty-millionth.  So  the  force  to  be  measured  was  one  twenty- 
millionth  of  the  weight  of  this  small  ball.  In  the  interferometer 
the  approach  of  the  small  ball  to  the  large  one  produced  a  dis- 
placement of  seven  whole  fringes. 

In  order  that  this  instrument  may  yield  the  best  results,  great 
care  must  be  exercised  in  its  construction.  The  runways  of  the 
frame  are  straightened  with  exactitude  by  a  method  due  to  Mr. 
F.  L.  O.  Wadsworth.  The  optical  surfaces  of  the  planes  and 
mirrors  in  the  original  designs  were  from  the  master  hand  of 
Mr.  John  A.  Brashear  of  Allegheny,  Pennsylvania.  Each  mirror 
is  free  from  any  irregularity  greater  than  1/880,000  inch,  and 
the  opposite  faces  of  the  mirrors  must  be  parallel  within  one  sec- 
ond of  arc,  or  1/1,296,000  part  of  a  circle.1 

Now  for  a  word  as  to  Professor  Michelson's  suggestion  that 
an  unvarying  unit  of  measurement  may  be  found  in  a  certain 
light-wave,  as  observed  in  the  interferometer. 
Everybody  knows  that  each  chemical  element       A  Light- Wave 
burns  with  colors  of  its  own.  When  we  see  red     as  an  Unvarying 
fire   bursting    from    a    rocket    we   know    that       Unit  of  Length, 
strontium  is  ablaze;  when  the  tint  is  green  it 

1  Interferometers  in  a  variety  of  designs  are  manufactured  by  William 
Gaertner  &  Co.,  5347  Lake  Avenue,  Chicago. 


218  MEASUREMENT 

tells  us  that  copper  is  on  fire,  as  when  a  trolley-wheel  jumps 
from  its  electric  wire.  When  these  sources  of  light  are  looked  at 
through  an  accurate  prism  of  glass  in  a  spectroscope  they  form 
characteristic  spectra,  and  these  spectra  in  their  peculiarities  of 
color  reveal  what  elements  are  aflame.  In  most  cases  the  rays 
from  an  element  form  a  highly  complicated  series;  to  this  rule 
cadmium,  a  metal  resembling  zinc,  is  an  exception.  It  emits  a 
red,  a  green,  and  a  blue  ray ;  the  wave-lengths  of  these  rays  Pro- 
fessor Michelson  proposes  as  a  basis  of  reference  for  the  metallic 
standards  of  length  adopted  by  the  nations  of  Europe  and  Amer- 
ica. He  says :  "We  have  in  the  interferometer  a  means  of  com- 
paring the  fundamental  standard  of  length  with  a  natural  unit — 
the  length  of  a  light-wave — with  about  the  same  order  of  accu- 
racy as  is  at  present  possible  in  the  comparison  of  two  metre- 
bars,  that  is,  to  one  part  in  twenty  millions.  The  unit  depends  on 
the  properties  of  the  vibrating  atoms  of  the  radiating  substance, 
and  of  the  luminiferous  ether,  and  is  probably  one  of  the  least 
changeable  qualities  in  the  material  universe.  If  therefore  the 
metre  and  all  its  copies  were  destroyed,  they  could  be  replaced  by 
new  ones,  which  would  not  differ  among  themselves.  While  such 
a  simultaneous  disaster  is  practically  impossible,  it  is  by  no 
means  sure  that  notwithstanding  the  elaborate  precautions  that 
have  been  taken  to  ensure  permanency,  there  may  not  be  slow 
molecular  changes  going  on  in  all  the  standards,  changes  which 
it  would  be  impossible  to  detect  except  by  some  such  method  as 
that  here  presented." 

Thus,  by  dint  of  mechanical  refinements  such  as  the  world  never 
saw  before,  some  of  the  smallest  units  revealed  to  the  eye  become 
the  basis  of  all  measurement  whatever,  reaching  at  last  those 
cosmical  diameters  across  which  light  itself  is  the  sole  messenger. 
In  the  early  days  of  spectroscopy  many  doubters  said,  What 
good  is  all  this?  Since  then  a  full  reply  has  been  rendered  to 
their  question  and,  at  this  unexpected  point,  the  spectroscopic 
examination  of  an  unimportant  metal  may  afford  a  measuring 
unit  of  ideal  stability.  Cases  like  this  suggest  the  query,  Is  any 
knowledge  whatever  quite  worthless  ? 


CHAPTER  XVII 


,      MEASUREMENT-CVmtfn*** 

Weight,  Time,  Heat,  Light,  Electricity  measured  with  new  precision  .  .  . 
Exact  measurement  means  interchangeable  designs,  and  points  the 
way  to  utmost  economies  .  .  .  The  Bureau  of  Standards  at  Washington 
.  .  .  Measurement  in  expert  planning  and  reform. 

OUR  grandfathers  supposed  that  trade  began  in  barter;  we 
have  been  able  to  go  one  step  further  back  in  history  to 
find  that  barter  followed  upon  the  custom  of  exchanging  presents. 
This  custom,  among  shrewd  and  self-respecting  people,  came  at 
length  to  a  degree  of  fairness,  and  led  to  rough 

and  ready  modes  of  weighing,  gradually  im-      The  Balance  *n 
i       T     xt-     T»  -A.-  1     TI/T  •  Measurement, 

proved.     In  the  British  Museum,  in  a  paqyrus 


Ancient  Egyptian  balance. 

319 


220 


MEASUREMENT 


of  Hunnafer,  who  lived  in  Egypt  thirty-three  centuries  ago,  we 
have  pictured  a  well-constructed  balance  of  equal  arms,  in  which 
a  feather  is  outweighing  a  human  soul.  In  its  successive  im- 


A  Rueprecht  balance. 


provements  the  balance  registers  the  progress  of  many  arts  and 
sciences,  and  in  its  turn  has  promoted  them  all.  It  must  be  built 
of  a  metal,  or  an  alloy,  hard,  durable,  and  not  easily  corroded. 
Its  centre  of  motion  should  be  a  little  above  its  centre  of  gravity ; 
its  knife  edge  should  have  an  angle  of  about  60  degrees.  Ap- 
pliances must  render  it  easy  to  lift  the  weighing  apparatus  when 
out  of  use,  so  that  unnecessary  wear  of  the  knife  edge  may  be 


WEIGHING  221 

avoided,  as  well  as  needless  strain  throughout  the  structure.  Air 
currents  should  be  kept  off  by  a  suitable  case,  or,  better  still,  the 
instrument  should  be  enclosed  in  a  receiver  exhausted  of  air  alto- 
gether. The  weights,  made  with  scrupulous  care  of  standard 
metal  or  alloy,  should  be  guarded  from  tampering,  abrasion,  and 
corrosion,  from  dirt  or  other  accretions.  A  weighing  should  be 
slowly  performed,  the  weights  placed  in  the  center  of  one  pan, 
the  object  weighed  in  the  center  of  the  other  pan;  to  eliminate 
errors  due  to  inequality  in  the  length  of  arms,  the  article  weighed 
and  the  weights  are  then  made  to  exchange  places.  The  platform 
should  be  of  the  utmost  strength  and  rigidity,  so  as  precisely  to 
maintain  its  level  at  all  times. 

As  long  ago  as  1798  a  balance  was  erected  having  an  accuracy 
of  one  part  in  1,600,000;  fifty  years  later  ten-fold  greater  accu- 
racy had  been  attained ;  to-day  results  much  more  astonishing  are 
achieved.  A  precision  balance  manufactured  by  Messrs.  Albert 
Rueprecht  &  Son,  Vienna,  is  shown  on  page  220,  as  furnished 
in  1902  to  the  International  Bureau  of  Weights  and  Measures  at 
Sevres,  France.  It  is  provided  with  means  for  applying  the 
smallest  weights  of  platinum  from  a  distance  of  three  to  four 
metres,  so  as  to  guard  against  perturbations  due  to  the  warmth 
of  an  operator's  body.  The  weights  may  be  shifted  from  one 
pan  to  the  other,  and  the  oscillations  observed  through  a  tele- 
scope, at  a  distance  of  four  metres.  This  balance  will  detect  the 
1/500  of  a  milligram  when  weighing  a  mass  of  500  grams,  or  one 
part  in  250,000,000.  Such  balances,  and  those  of  Paul  Bunge,  of 
Hamburg,  require  ten  to  twenty  months  of  skilled  labor  for  their 
completion.  The  International  Bureau  of  Weights  and  Measures 
has  a  balance  of  extraordinary  sensitiveness  at  the  Pavilion  de 
Breteuil,  Sevres,  where  the  work  of  the  Bureau  goes  forward. 
This  instrument  measures  the  difference  in  the  attraction  of  the 
earth  for  a  mass  of  one  kilogram  when  that  weight  is  moved 
nearer  to  or  farther  from  the  centre  of  the  earth  by  as  little  as 
one  centimetre.  Thus  placing  two  weights,  of  common  shape, 
each  a  kilogram,  one  on  top  of  the  other,  and  two  other  weights 
in  the  other  pan  beside  one  another,  would  introduce  a  note- 
worthy difference  in  a  comparison. 

At  the  very  dawn  of  civilization,  the  day,  however  crudely,  was 


222  MEASUREMENT 

divided  into  parts.  These  parts,  long  afterward,  probably  in 
Babylonia,  became  the  twenty-four  hours  which  have  descended 
to  us.  The  means  of  time-keeping  came  first,  in  all  likelihood, 
from  measuring  the  simple  shadow  of  a  stick,  the  gnomon,  still 

set   up  as  a   sun-dial   in  our  gardens.     Next 
Measurement         came  an  hour_glass  with  its   falling  sand  .  the 
ox  Time.  . 

clepsydra,  with  its  water  dropping  from  a  jar; 

the  burning  of  candles  definite  in  length.  At  last  came  the  su- 
preme discovery  that  a  pendulum,  of  given  length,  if  kept  in  one 
place  oscillates  in  an  unvarying  period,  be  its  arc  of  motion  long 
or  short.  Tradition  has  it  that  in  Arabia,  about  the  year  1000 
A.  D.,  the  pendulum  was  used  in  time-keeping.  Granting  this  to 
be  true,  we  must  nevertheless  give  Galileo  credit  for  his  indepen- 
dent discovery  as  he  observed  the  swaying  lamp  of  the  cathedral 
at  Pisa,  early  in  the  seventeenth  century.  In  1657  Huygens  em- 
ployed a  pendulum  in  the  construction  of  a  clock  which,  of 
course,  displayed  a  new  approach  to  accuracy.  In  1792  Borda 
and  Cassini  had  improved  their  time-pieces  so  as  to  be  correct 
within  one  part  in  375,000,  that  is  to  one  second  in  104  hours. 
For  the  sake  of  portability,  clocks  were  gradually  reduced  in 
size  until  they  became  watches.  Instead  of  a  pendulum  they  were 
furnished  with  its  equivalent,  a  balance  wheel,  Pierre  Le  Roy 
having  discovered  that  there  is  in  every  spring  a  certain  length 
where  all  the  vibrations,  great  or  small,  are  performed  in  ap- 
proximately the  same  period.  For  actuation,  watches  were  pro- 
vided with  mainsprings  which  have  steadily  undergone  improve- 
ment in  quality  and  in  placing. 

Many  refinements  have  brought  the  time-keeper  for  the  ship, 

the  observatory,  the  railroad,  to  virtual  perfection.     Its  wheels, 

pinions,  balance-staffs  are  manufactured  auto- 

Time-Pieces        matically,  as  at  Waltham,  Massachusetts,  to  an 
Improved.  **' 

accuracy  of  1/5000  inch  or  even  less,  thanks  to 

that  great  inventor,  Mr.  Duane  H.  Church.  In  modern  watch- 
making the  most  durable  materials  are  used,  magnetic  perturba- 
tions are  avoided  by  employing  alloys  insensitive  to  magnetism, 
and  the  effects  of  fluctuating  temperatures  are  withstood  by  Earn- 
shaw's  compensated  balance  wheel.  This  wheel  is  in  halves,  each 


TIME 


223 


Earnshaw  compensated  bal- 
ance wheel  for  watches. 


nearly  semicircular  and  attached  at  one  end  to  a  stout  diameter. 
Its  outer  rim,  being  made  of  brass,  when  warmed  expands  more 
than  its  inner  rim  of  steel.  Thus, 
in  a  rising  temperature  the  wheel 
curves  inward  with  its  duly  placed 
weights,  so  that  the  reduction  in 
elasticity  of  the  hair-spring  caused 
by  heat  is  compensated.  Experi- 
ments are  afoot  which  look  toward 
a  marked  improvement  in  the 
making  of  time-pieces,  by  using 
invar,  a  nickel-steel  with  prac- 
tically no  expansibility  by  heat. 
This  alloy  is  already  employed 
for  pendulums  with  satisfactory 
results,  both  at  the  Naval  Ob- 
servatory and  at  the  Bureau  of  Standards,  in  Washington.  It 
has  been  described  on  page  169. 

At  the  Paris  Observatory  the  standard  clock,  by  Winnerl,  is  in 

a  vault  twenty-seven  metres  underground.     At  that  depth  the 

temperature  changes  are  less  than  one  fifth  of 

The  Best  Clocks     a  degree  during  the  year,  yet  the  effect  of  baro- 

in  the  World.  metric  changes,  on  the  rate  of  the  clock  have 
proved  to  be  serious.  This  difficulty  is 
avoided  in  the  Naval  Observatory  at  Washington,  by  enclosing 
the  standard  clock  in  an  air-tight  case  within  which  the  air  is 
reduced  to  a  pressure  lower  than  that  ever  shown  by  a  barometer 
at  that  level.  To  avoid  risks  of  air  leaking  through  this  case  were 
it  to  be  pierced  by  a  moving  axle,  this  clock  is  actuated  by  weights 
lifted  electrically  by  a  small  primary  battery.  The  slight  electric 
current  required  has  no  perturbing  effect  on  the  clock.  This  time- 
piece, provided  with  an  escapement  of  great  excellence,  was 
manufactured  by  Clemens  Riefler  of  Munich. 

At  the  Observatory  of  the  Case  School  of  Applied  Science, 
Cleveland,  Ohio,  another  Riefler  clock  has  a  mean  error  of  but 
.015  second  per  day.  This  means  that  in  a  year  the  total  error  is 
not  more  than  5.475  seconds,  or  one  part  in  5,760,000  of  the  365 


224 


MEASUREMENT 


days.  Such  errors,  minute  as  they  are,  give  a  good  deal  of 
trouble  when  they  are  irregular,  that  is,  when  the  clock  is  some- 
times slow,  sometimes  fast,  in  a  fashion  apparently  lawless. 

When  the  divergences  are 
fairly  constant  they  can 
usually  be  traced  to  their 
source,  making  it  feasible  to 
apply  a  remedy. 

A  pendulum  which  swings 
once  in  a  second  at  the  base 
of  a  tall  tower  will  require 
for  the  same  travel  a  little 
more  than  a  second  when 
borne  to  the  top  of  the  tower, 
because  then  further  from 
the  centre  of  the  earth.  Still 
greater  will  be  the  difference 
in  its  periods  as  it  swings 
first  at  the  base  of  a  moun- 
tain and  next  at  its  summit. 
A  pendulum,  therefore,  is  a 
means  of  learning  the  force 
of  gravity  at  a  given  place, 
and  without  sacrifice  of  ac- 
curacy it  is  well  that  it 
should  be  as  small  as  pos- 
sible. In  1890,  Professor 
T.  C.  Mendenhall,  then 
superintendent  of  the  United 
States  Coast  and  Geodetic 
Survey,  designed  a  pendulum 
Riefler  clock.  one  fourth  the  length  of  those 

previously  used,  and  of  ad- 
mirable precision.     Afterward  pendulums  were  built  of  dimen- 
sions  further  reduced  to  about  two  and  one 

Ascertaining  the      half  inches   {n   length     with   periods  of   OScilla- 
Force  of  Gravity.  °  jot 

tion   of  one   fourth  of   a  second,     buch  pen- 
dulums are  easily  carried  to  stations  difficult  of  access,  and  have 


HEAT  225 

been  employed  on  the  summits  of  high  mountains,  including 
Pike's  Peak :  their  indications  agree  well  with  those  of  the  larger 
and  somewhat  cumbersome  apparatus  previously  used. 

Much  the  most  convenient  means  of  measuring  temperature  is 
the  common  glass  tube  filled  with  mercury.    This  metal  is  chosen 
because  a  liquid,  and  because  it  varies  extremely 
in  bulk  when  warmed  or  cooled.     Materials  of      Heat  Measured. 
parallel   susceptibility  are  adopted   for  instru- 
ments which  measure  the  intensity  of  magnetism  or  of  electricity, 
the  working  core  of  the  instrument  being  made  of  a  substance 
highly  responsive  to  magnetism  or  to  electricity. 

A  mercurial  thermometer,  for  all  its  convenience,  has  its  ac- 
curacy assailed  on  more  sides  than  one.  When  the  barometric 
pressure  rises,  the  bulb  is  compressed ;  when  the  barometer  falls, 
the  bulb  enlarges  by  virtue  of  the  diminution  in  atmospheric  pres- 
sure. Further,  when  its  graduated  tube  is  upright  the  mercury 
exerts  a  distending  pressure  which  introduces  error.  At  all  tem- 
peratures the  metal  is  giving  off  a  vapor  which  has  tension,  in  its 
upper  ranges  entailing  marked  inaccuracies.  The  glass  itself  of 
which  the  instrument  is  made,  when  of  ordinary  composition, 
spontaneously  undergoes  changes  of  volume.  While  this  is  a 
minor  source  of  error  it  may  be  almost  completely  avoided  by 
using  a  boro-silicate  glass  from  the  factory  of  Schott  &  Genossen, 
at  Jena.  Other  substances  than  mercury  are  employed  in  thermom- 
eters with  gratifying  results.  Hydrogen  gas  is  found  very 
suitable  within  the  interval  from— 30°  to  200°  Centigrade.  Pen- 
tane  serves  in  temperatures  reaching  down  to — 180°. 

But  it  is  in  alliances  with  electricity  that  the  measurement  of 
heat  has  its  broadest  scope  and  utmost  exactitude.  It  was  long 
ago  remarked  that  heating  a  metallic  conductor  increases  its  re- 
sistance to  the  flow  of  an  electric  current;  to  measure  that 
resistance  in  a  platinum  wire  serves,  therefore,  to  measure  its 
temperature.  An  instrument  on  this  principle  is  the  bolometer  of 
the  late  Professor  S.  P.  Langley,  of  Washington.  Through  a 
strip  of  platinum  barely  1/500  inch  in  width,  and  less  than  1/5000 
inch  in  thickness,  a  current  of  electricity  flows  continuously. 
When  radiation,  visible  or  invisible,  on  occasion  from  a  star,  falls 
upon  it,  the  strip  when  warmed  by  as  little  as  one  millionth  of  a 


226  MEASUREMENT 

degree  duly  records  the  fact.  An  instrument,  modified  prom  the 
Crookes  radiometer  by  Professor  E.  F.  Nichols  of  Columbia  Uni- 
versity, New  York,  is  more  sensitive  still.  An  exhausted  hollow 
metal  block  has  a  window  of  fluorite,  a  mineral  transparent  to 
ether  vibrations  of  a  long  range  of  frequencies.  Suspended  inside 
the  block  is  a  fine  quartz  fibre  supporting  a  horizontal  bar,  at  the 
ends  of  which  are  attached  thin  plates  of  mica,  blackened  on  one 
side.  Rays  passing  through  the  fluorite  window  strike  the  black- 
ened side  of  the  mica,  which  is  parallel  and  opposite  to  it.  The 
resulting  rise  in  temperature  causes  the  vane  to  revolve  against 
the  torsion  of  the  quartz  fibre.  The  angle  of  torsion  when  thermal 
equilibrium  is  reached,  measures  the  intensity  of  the  incident 
radiation. 

Another  principle  is  adopted  in  the  electrical  instruments  which 
expose  to  heat  a  junction  of  two  different  materials,  usually 
metallic,  giving  rise  to  an  electric  current,  easily  measured.  Ex- 
perience shows  that  the  most  satisfactory  couples  for  temperatures 
between  300°  C.  (570°  F.)  and  1600°  C.  (2900°  F.)  are  those 
devised  by  M.  Le  Chatelier,  one  half  consisting  of  pure  platinum, 
the  other  half  an  alloy  of  ten  per  cent,  rhodium  and  ninety  per 
cent,  platinum.  Such  instruments  are  indispensable  in  the  arts 
which  employ  high  temperatures.  In  producing  chlorine  by  the 
Deacon  process,  or  in  the  baking  of  porcelain,  an  undue  variation 
of  temperature  of  only  twenty  degrees  may  cause  a  complete 
failure  of  the  operation. 

It  is  probable  that  about  one  half  the  electricity  from  the 
dynamos  of  America  is  sent  into  lamps,  and  this  is  but  part  of 
the  whole  outlay  for  light,  still  chiefly  pro- 
The  Measurement  duced  by  petroleum  and  gas.  Hence  the  im- 
of  Light.  portance  of  measuring  the  light  from  lamps, 

jets,  and  mantles  of  various  kinds,  and  testing 
the  efficiency  of  shades  and  reflectors.  First  of  all  comes  the  de- 
cision as  to  a  standard  for  comparison.  Great  Britain  has  adopted 
the  Harcourt  lamp,  consuming  pentane,  as  a  standard  for  ten 
candle-power,  referring  to  the  old  time  candle  of  spermaceti. 
Germany  employs  the  amylacetate  lamp  introduced  by  Von  Hef- 
ner Alteneck,  as  a  standard  for  its  Hefner  unit  of  illumination. 
Both  lamps  share  in  a  difficulty  which  attends  all  combustion: 


LIGHT 


227 


atmospheric  conditions  which  vary  from  hour  to  hour,  from  place 
to  place,  greatly  affect  the  intensity  of  a  flame.  Hence  incan- 
descent lamps,  which  have  been  compared  with  these  fundamental 
standards,  are  used  as  working  standards.  They  can  be  operated 
by  a  uniform  current  of  specified  voltage,  and  after  a  hundred 
hours'  use  their  constancy  of  radiation  for  a  considerable  period 
is  remarkable. 

Having  settled  upon  a  standard  candle  or  lamp  the  measure- 


B 


Photometer.     A,  standard  candle.     B,  gas  flame.     S,  sliding  frame. 


ment  of  light  demands  extreme  care,  and,  at  the  best,  can  never 
approach  the  accuracy  of  other  laboratory  measurements.  Many 
photometers  have  been  invented,  some  of  them  highly  elaborate, 
but  the  type  oftenest  used  remains  in  essence  the  simple  instru- 
ment long  ago  devised  by  Bunsen.  On  a  frame  supported  by  a 
stand,  S,  is  stretched  a  sheet  of  white  paper  in  the  centre  of  which 
is  a  grease  spot.  This  spot  allows  more  light  to  pass  through 
it  and  consequently  reflects  less  than  the  unmarked  portion  of 
the  paper.  If  the  sheet  is  more  strongly  lighted  from  behind 
than  from  in  front,  it  appears  bright  on  a  dark  ground.  If  it  is 
illuminated  more  strongly  in  front  than  at  the  back  it  will  seem 
dark  upon  a  bright  ground.  When  equal  lights  fall  on  both  sides, 
the  spot  becomes  invisible,  since  it  can  then  appear  neither  darker 
nor  brighter  than  the  surrounding  paper.  In  its  simplest  use  the 
screen  is  placed  between  a  standard  candle  or  lamp  at  A  and  the 
light  to  be  measured  at  B :  the  screen  is  moved  along  its  graduated 
slide  until  the  grease  spot  vanishes.  If  the  screen  is  twice  as  far 


228  MEASUREMENT 

from  B  as  from  A  when  the  spot  disappears,  then  B  is  four  times 
as  intense  as  A  in  light;  if  the  screen  were  thrice  as  far  from  B 
as  from  A,  then  B  would  be  nine- fold  as  bright  as  A,  the  intensity 
of  light  diminishing  as  the  square  of  the  distance  of  its  source. 

An  open-arc  lamp,  without  a  reflector,  sends  to  the  ground  a 
fairly  wide  ring  of  brilliant  rays;  on  both  sides  of  that  ring  the 
illumination  is  feeble.  Other  sources  of  light  also  vary  a  good 
deal  in  the  brilliancy  of  the  beams  which  they  emit  in  various 
planes.  It  is  therefore  usual  to  measure  the  light  from  a  lamp  as 
sent  forth  in  all  planes,  or  at  least  in  its  principal  planes.  When 
incandescent  lamps  are  brought  to  a  photometer  they  are  as  a 
rule  placed  on  a  spindle  turning  so  swiftly  that  their  mean  hori- 
zontal candle-power  may  be  read  at  once.  For  measuring  the 
mean  spherical  intensity  a  photometer  devised  by  Professor  Mat- 
thews of  Purdue  University  is  employed.  This  apparatus  has  a 
series  of  mirrors  arranged  in  a  semicircle  around  a  lamp,  reflect- 
ing all  the  received  light  upon  a  single  surface. 

Light  may  have  great  brilliancy  and  yet  be  undesirable  from 
its  color;  we  are  all  familiar  with  the  havoc  that  gas  light  may 
play  with  hues  of  blossom  and  leaf  that  in  sunshine  are  beautiful. 
Through  ages  untold  the  human  eye  has  been  seeing  by  rays  from 
the  sun,  and  from  immemorial  habit  is  best  served  by  light  of 
similar  quality.  A  simple  instrument,  the  spectrometer,  casts 
upon  a  screen  the  spectrum  from  a  mercury  tube,  a  Nernst  lamp, 
a  Welsbach  mantle,  or  other  illuminant,  and  enables  us  to  com- 
pare it  with  the  spectrum  of  sunshine.  Then,  as  in  placing  a  light 
pink  shade  over  a  Welsbach  mantle,  we  act  on  the  intimations  of 
analysis  greatly  to  the  relief  of  the  eye. 

An  incandescent  bulb  or  mantle  may  be  satisfactory  both  in 
brilliancy  and  color,  but  a  further  question  is,  How  long  will  the 
filament  or  the  mantle  last,  and  at  what  point  in  deterioration 
should  it  be  discarded?  Tests  during  the  first,  the  fiftieth,  the 
hundredth,  and  other  successive  hours  will  tell  us  how  much 
the  intensity  falls  off.  Just  when  a  bulb  or  a  mantle  should  be 
dismissed  from  service  depends  partly  on  the  rate  of  deteriora- 
tion, and  partly  on  the  prices  of  bulbs  and  current,  of  mantles  and 
gas. 

Hardly  t  less   important  than  testing  sources  of  light  is   the 


IN  THE  OBSERVATORY  229 

investigation  of  their  reflectors  and  shades.  As  a  rule  our  lamps 
are  too  brilliant,  and  in  many  cases  they  send  their  light  in  waste- 
ful directions.  It  is  a  general  and  absurd  practice  to  buy  a 
dollar's  worth  of  light  and  then  kill  sixty  cents'  worth  of  it  with 
a  thick  opal  or  cut-glass  shade.  Examination  with  the  photom- 
eter has  revealed  that  many  popular  patterns  of  reflectors  and 
shades  are  most  ineffective,  while  those  of  the  Holophane  make, 
when  kept  scrupulously  clean,  send  the  light  just  where  it  does 
most  good  and  at  the  lowest  possible  expenditure  of  energy.  This 
theme  has  attention  on  page  78.* 

The  sky  has  been  the  supreme  field  for  measurements  more 
refined  from  age  to  age.     Professor  William  Stanley  Jevons,  in 
"Principles  of  Science,"  says :  "At  Greenwich 
Observatory  in  the  present  day,  the  hundredth       The  Sky  as  a 
part  of  a  second  is  not  thought  an  inconsider-  Field  for 

able  portion  of  time.  The  ancient  Chaldeans  Measurement, 
recorded  an  eclipse  to  the  nearest  hour,  and 
even  the  early  Alexandrian  astronomers  thought  it  superfluous  to 
distinguish  between  the  edge  and  centre  of  the  sun.  By  the  intro- 
duction of  the  astrolabe,  Ptolemy  and  the  later  Alexandrian 
astronomers  could  determine  the  places  of  the  heavenly 
bodies  within  about  ten  minutes  of  arc.  But  little  progress  then 
ensued  for  thirteen  centuries,  until  Tycho  Brahe  made  the  first 
great  step  toward  accuracy,  not  only  by  employing  better  instru- 
ments, but  even  more  by  ceasing  to  regard  an  instrument  as  cor- 
rect. Tycho,  in  fact,  determined  the  errors  of  his  instruments, 
and  corrected  his  observations.  He  also  took  notice  of  the  effects 
of  atmospheric  refraction,  and  succeeded  in  attaining  an  accuracy 
often  sixty  times  as  great  as  that  of  Ptolemy. 

"Yet  Tycho  and  Hevelius  often  erred  several  minutes  in  4he 
determination  of  a  star's  place,  and  it  was  a  great  achievement  of 
Roemer  and  Flamsteed  to  reduce  this  error  to  seconds.  Bradley, 
the  modern  Hipparchus,  carried  on  the  improvement,  his  errors 
in  right  ascension  being  under  one  second  of  time,  and  those  of 

*A  capital  treatise  on  the  subject  of  lighting,  and  the  measurement  of 
light,  is  Louis  Bell's  "Art  of  Illumination."  New  York,  McGraw  Publish- 
ing Co.,  1902.  $2.50.  Its  author  (August,  1906)  is  preparing  a  new  and 
revised  edition. 


230 


MEASUREMENT 


declination  under  four  seconds  of  arc  according  to  Bessel.  In  the 
present  day  the  average  error  of  a  single  observation  is  probably 
reduced  to  the  half  or  quarter  of  what  it  was  in  Bradley's  time; 
and  further  extreme  accuracy  is  attained  by  the  multiplication  of 
observations,  and  their  skilful  combination  according  to  the 
method  of  least  squares.  Some  of  the  more  important  constants, 
for  instance  that  of  nutation,  have  been  determined  within  the 
tenth  part  of  a  second  of  arc. 

"It  would  be  a  matter  of  great  interest  to  trace  out  the  depen- 
dence of  this  vast  progress  upon  the  introduction  of  new  instru- 
ments. The  astrolabe  of  Ptolemy,  the  telescope  of  Galileo,  the 
pendulum  of  Galileo  and  Huygens,  the  micrometer  of  Horrocks, 
and  the  telescopic  sights  and  micrometer  of  Gascoyne  and  Picard, 
Roemer's  transit  instrument,  Newton's  and  Hadley's  quadrant, 
Dollond's  achromatic  lenses,  Harrison's  chronometer,  and  Rams- 
den's  dividing  engine  —  such  were  some  of  the  principal  additions 
to  astronomical  apparatus.  The  result  is  that  we  now  take  note 
of  quantities  1/300,000  or  1/400,000  the  size  of  the  smallest  ob- 
servable in  the  time  of  the  Chaldeans." 

As  important  as  the  measurements  of  the  astronomer  are  those 
of  the  electrician.  It  was  as  recently  as  1819  that  Oersted,  a 
Danish  physicist,  published  a  discovery  which 

became   a    foundation    stone   of   electrical   en- 

.  .        . 

gmeermg,  and  upon  which  rises  the  art  of  elec- 


Electricity 

Measured. 


AC— -.'--- -z 


Compass  needle  deflected  by  an  electric  current  borne 
in  a  wire. 


ELECTRICITY 


231 


trical  measurement.  He  observed  that  when  an  electric  current  is 
passing  through  a  wire,  a  nearby  magnetic  needle  tends  to  place 
itself  at  right  angles  to  the  wire,  the  deflection  varying  with  the 
strength  of  the  current.  When  instead  of  a  wire,  a  coil,  duly  in- 
sulated, is  employed  to  carry  the  current,  effects  much  more  de- 
cided are  displayed.  At  first  current-measurers,  or  galvanometers, 


Compass  needle  deflected  by  an  electric  current  borne 
in  a  coil. 

employed  simple  compass  needles;  these  proved  to  be  unsatis- 
factory. They  were  affected  by  the  variations  which  occur  in  the 
intensity  of  the  earth's  magnetism;  and  no  matter  how  carefully 
a  needle  was  made,  it  varied  in  strength 
from  week  to  week,  from  year  to  year; 
again,  a  current  might  be  so  strong  as  to 
create  magnetism  overwhelming  in  com- 
parison with  that  of  the  earth,  and  quite 
beyond  the  measuring  power  of  a  com- 
pass needle.  A  galvanometer  on  a  plan 
due  to  Professor  James  Clerk  Maxwell, 
employs  a  permanent  magnet,  or  an  elec- 
tro-magnet, which  is  stationary,  between 
the  poles  of  which  may  freely  turn  a  coil 
bearing  the  current  to  be  measured.  This 
current  in  the  case  of  an  ocean  cable  is  so 
weak  that  no  other  means  of  indication 

will  serve.   Lord  Kelvin's  recording  apparatus  for  such  a  cable  is 
a  galvanometer  on  this  principle.  In  order  to  concentrate  the  lines 


Suspended  coil  with  D, 

soft  iron  core.     N,  S, 

magnetic   poles. 


232 


MEASUREMENT 


of  magnetic  force  on  the  vertical  sides  of  the  coil,  a  piece  of  soft 
iron,  D,  is  fixed  between  the  poles  of  the  magnet.  This  iron  be- 
comes magnetized  by  induction,  so  as  to  produce  a  very  powerful 
field  of  force,  in  the  minute  spaces  between  it  and  the  two  mag- 
netic poles,  through  which  spaces  the  vertical  sides  of  the  coil  are 
free  to  move.  Instruments  of  this  kind,  developed  by  D'Arson- 
val,  are  known  by  his  name. 

Instruments  for  electrical  measurement,  with  stationary  magnets 
and  moving  coils,  of  great  excellence,  are  manufactured  by  the 
Weston  Company,  Waverly  Park,  New  Jersey. 
Their  accuracy  rests  upon  several  important 
discoveries  by  Dr.  Edward  Weston :  first,  a 
method  of  making  a  magnet  which  is  really  permanent,  retaining 
its  original  strength  for  a  long  time:  second,  by  the  prep- 
aration of  a  remarkable  group  of  alloys  which  under  ordinary 
variations  of  temperature  manifest  scarcely  any  change  in  con- 


Weston 
Instruments. 


Weston  voltmeter. 


ductivity,  and  which  set  up  but-  little  thermo-electric  action  as  they 
touch  other  metals  in  an  instrument.  Let  us  see  how  a  Weston 
voltmeter,  or  measurer  of  electric  pressure,  is  constructed. 


ELECTRICITY  233 

A  light  rectangular  coil  of  copper  wire,  C,  is  wound  on  an  alu- 
minium frame  pivoted  in  jeweled  bearings  so  as  to  be  free  to 
rotate  in  the  ring-like  space  between  an  inner  cylindrical  soft  iron 
core,  K,  and  the  pole  pieces  P  and  P  of  the  permanent  magnet,  M. 
A  light  aluminium  pointer,  p,  is  attached  to  the  coil  and  is  free  to 
move  across  the  scale,  D.  The  current  enters  the  coil  through  the 
two  spiral  springs  S  and  S,  which  serve  also  to  control  the  move- 
ment of  the  coil.  When  a  current  passes  through  the  coil  the 
dynamic  action  between  the  current  and  the  magnetic  field  tends 
to  rotate  the  coil,  and  the  position  of  equilibrium  between  this 
force  and  the  torsion  of  the  springs,  indicated  by  the  pointer, 
measures  the  current  passing  through  the  coiL  Because  the 
magnetic  field  is  practically  unvarying  throughout,  and  the  torsion 
of  the  springs  is  proportionate  to  their  deflection,  the  scale  is  vir- 
tually uniform.  This  is  not  assumed  in  their  manufacture,  how- 
ever, for  each  instrument  is  calibrated  by  direct  reference  to 
standards.  As  the  aluminium  frame  moves  through  the  magnetic 
field,  slight  currents  are  generated  within  the  metal ;  these  serve 
to  dampen  vibrations  so  that  the  pointer  comes  to  rest  almost  in- 
stantly without  friction.  That  the  magnetic  field  may  have  the 
utmost  strength,  the  air  gap  in  which  the  coil  rotates  is  made 
as  narrow  as  possible;  this  is  ensured  by  workmanship  of  the 
highest  skill,  and  by  tools  specially  designed.  The  hardened  steel 
pivots  are  ground  and  centered  as  in  the  best  watch-making:  the 
coil  is  balanced  by  means  of  adjustable  weights  so  that  none  but 
electrical  forces  may  come  into  play.  In  a  Weston  voltmeter  of 
regular  type,  the  maximum  current  required  for  a  full  scale- 
deflection  is  only  o.oi  ampere.  Instruments  of  much  higher  sen- 
sibility are  constructed  for  measuring  insulation,  requiring  but 
0.0006  ampere  for  the  same  deflection.  So  much  for  the  task 
of  measuring  electrical  pressure. 

For  measuring  electrical  currents,  which  differ  from  pressures 
as  the  quantity  of  water  flowing  in  a  pipe  differs  from  the  pressure 
of  that  water  as  shown  in  a  common  gauge,  a  Weston  ammeter, 
or  ampere-meter,  may  be  employed.  It  is  similar  to  the  voltmeter 
just  described,  being  in  fact  a  milli-voltmeter  actuated  by  the 
difference  in  electrical  potential,  or  pressure,  between  the  ter- 
minals of  a  standard  resistance,  the  shunt,  through  which  a  defi- 


234  MEASUREMENT 

nite  fraction  of  the  current  passes.  It  is  as  if  a  known  part  of 
the  flow  of  a  river  being  measured,  the  volume  of  the  whole 
stream  is  learned. 

The  two  principal  alloys  discovered  by  Dr.  Weston,  and  used 
in  his  instruments,  are  manganin  and  nickelin.  Manganin  has 
about  twenty-five  times  the  resistance  of  copper,  and  increases 
in  resistance  about  o.ooooi  for  each  degree  Centigrade  through 
which  its  temperature  rises.  Nickelin  has  about  twenty-nine,  times 
the  resistance  of  copper,  and  decreases  in  resistance  about  0.00004 
for  each  degree  Centigrade  through  which  its  temperature  rises. 
These  and  other  alloys  used  in  construction  are  carefully  worked 
and  annealed  according  to  methods  perfected  in  years  of  ex- 
perience. After  a  wire  for  an  instrument  is  drawn,  its  fibres, 
being  in  a  state  of  unequal  strain,  undergo  an  artificial  aging  pro- 
cess so  that  their  resistance  shall  remain  unchanged  after  adjust- 
ment. The  Weston  instruments  are  based  on  the  international 
volt  and  ampere  adopted  by  the  National  Bureau  of  Standards 
at  Washington.  Instruments  of  the  regular  portable  type  have  a 
guaranteed  accuracy  of  one  part  in  400,  while  the  laboratory 
standard  semi-portable  instruments  are  guaranteed  to  one  part  in 
1000.  Weston  voltmeters  and  ammeters  are  constantly  being 
checked  after  years  of  active  service,  arid  are  found  correct  within 
the  guaranteed  limits  of  accuracy. 

This  remarkable  success  testifies  to  the  importance  of  asking, 
What  properties  are  needed  in  the  material  of  which  an  instrument 
is  to  be  built?  That  question  duly  answered,  it  becomes  a  task 
for  research  to  provide  these  materials,  that  skill  may  put  them 
together  in  compact  and  convenient  form.1 

Whether  in  the  laboratory  of  the  chemist  or  the  physicist,  in 

the  machine  shop  or  the  engine-room,  every  means  of  measurement 

must  be  based  on  standards  created  with  the 

The  Bureau  of       highest  skill  and  guarded  with  the  utmost  care. 
Standards  at  fe 


_         1      TT    •      1  o 
Washington         ^or  t"e  United  States  these  ultimate  standards, 

in    full   variety,   are   brought  together   at   the 

1ln  taking  notes  for  this  book  the  author  has  visited  many  factories, 
works,  and  mills.  In  design,  equipment,  and  operation  the  Weston  factory 
is  the  best  of  them  all  and  quite  above  criticism.  Admirable,  too,  are 
the  educational  and  social  features  of  this  establishment. 


BUREAU  OF  STANDARDS  235 

Bureau  of  Standards  at  Washington,  of  which  Dr.  S.  W.  Stratton 
is  director.  Here  are  safeguarded  copies  of  the  international 
metre  and  the  kilogram  adopted  by  Executive  Order  in  1893  as 
fundamental  units  of  length  and  mass ;  here,  too,  are  standard 
yards  and  pounds,  bearing  fixed  legal  relations  to  the  international 
metre  and  kilogram  The  Bureau  is  prepared  to  determine  the 
length  of  any  standard  up  to  fifty  metres,  to  calibrate  its  sub- 
divisions, and  to  determine  its  coefficient  of  expansion  for  ordinary 
temperatures.  To  the  credit  of  American  workmanship  be  it  said 
that  at  times  the  micrometers  received  from  leading  manufac- 
turers, for  use  in  workshops  of  the  best  class,  are  so  refined  in 
their  measurements  as  to  tax  to  the  utmost  the  resources  of  the 
Bureau.  Its  precision  balances,  by  Rueprecht  of  Vienna,  and 
Stuckrath  of  Berlin,  weigh  a  kilogram  within  1/200  part  of  a 
milligram,  that  is,  within  one  two-hundred-millionth  part  of  its 
load. 

In  the  department  of  electricity  a  resistance  may  be  measured 
all  the  way  from  1/100,000  of  an  ohm  to  100,000  ohms.  Here  are 
voltmeters,  and  wattmeters  of  the  best  types.  Magnetism,  as 
swiftly  summoned  or  dismissed  in  the  cores  of  dynamos  and 
motors,  is  here  measured  with  the  utmost  exactitude.  In  some  of 
the  instruments  fused  quartz  has  been  used  as  a  means  of  sus- 
pension because  its  high  elasticity  and  great  strength  allow  it  to  be 
drawn  as  extremely  fine  threads.  Dr.  K.  E.  Guthe,  now  of  the 
University  of  Iowa,  while  at  the  head  of  the  section  of  magnetic 
measurements,  found  that  fibres  equally  serviceable  may  be  drawn 
from  steatite,  or  soapstone,  such  as  forms  a  common  kind  of 
gas-burner.  Thick  quartz  threads  break  easily  when  bent,  those 
of  steatite  do  not. 

In  thermometry,  a  section  in  charge  of  Dr.  Waidner,  much  work 
goes  forward  in  testing  clinical  and  other  thermometers  for  manu- 
facturers. The  whole  range  of  heat  measurement  is  covered  by 
instruments  adapted  to  recording  the  highest  attainable  tempera- 
tures until  we  reach  apparatus  by  which,  through  observation  of 
its  light,  the  absolute  temperature  of  the  electric  arc  has  been 
found  to  be  3720°  C.  Measurements  of  light  proceed  in  another 
section.  Here  a  photometer  designed  by  Mr.  Edward  P.  Hyde, 
of  the  Bureau  staff,  has  reached  the  hitherto  unexampled  accuracy 


23(5 


MEASUREMENT 


of  one  part  in  200.  The  Bureau  has  an  extensive  workshop  where 
new  designs  for  improved  apparatus  are  constantly  in  hand.  For 
services  on  behalf  of  the  national  or  any  state  government  the 
Bureau  makes  no  charge ;  moderate  fees  are  required  from  firms 
and  individuals.  In  its  new  and  adequate  quarters  the  Bureau  is 
doing  work  as  authoritative  as  that  of  any  similar  institution  in 
the  world. 

In  manufacturing  modern  tools  and  machinery,  the  thousandth 
of  an  inch  is  the  usual  limit  of  allowable  error.     A  micrometer 
caliper  measuring  to  this  limit  is  here  shown. 
Refined  Measure-     jj^g  pj^h  of  jts  screw  js  4O  to  the  inch,  and 

the  beveled  edge  of  the  screw-thimble  is  divided 
into  25  parts,  so  that  motion  from  one  division 

to  the  next  takes  the  screw  1/25  of  1/40  of  an  inch,  or  i/iooo. 

By  carrying  refinement  a  step  farther,  I/ 10,000  of  an  inch  can  be 


ment  Improves 
Machinery. 


Micrometer  caliper  measuring  i-iooo  inch. 
Brown  &  Sharpe,  Providence. 


detected.  The  production  of  a  screw  such  as  this  was  simply 
impossible  by  the  lathe  as  used  almost  up  to  the  close  of  the 
eighteenth  century,  its  operator  holding  in  his  hand  a  gouge  or 
chisel.  Of  inestimable  importance  was  Henry  Maudslay's  inven- 
tion of  the  slide-rest  which  firmly  holds  the  tool,  moving  it  auto- 
matically along  the  wood  or  metal  being  cut.  See  illustration  on 
page  96.  James  Watt,  as  he  endeavored  to  improve  the  steam 
engine,  before  the  slide-rest  was  invented,  was  sorely  vexed 
and  thwarted  by  the  ill-shaped  containers  for  steam  which  served 


MECHANICAL  REFINEMENTS       237 


Plug  and  ring  for  standard 
measurements. 


him  as  cylinders.  Perhaps  the  chief  task  accomplished  by  the 
lathe  has  been  its  own  improvement,  so  that  to-day  surfaces  are 
readily  cut  by  its  tools  ac- 
curately to  within  a  thou- 
sandth part  of  an  inch. 
Vastly  beyond  this  feat  was 
Professor  H.  A.  Rowland's 
production  of  a  virtually 
perfect  screw,  which  enabled 
him  to  rule  on  concave 
gratings  5.9  inches  square, 
110,000  lines  with  such 

precision  that  the  error  between  any  two  of  the  lines  is  probably 
less  than  1/3,000,000  of  an  inch.  These  gratings  brought  to  view 
spectra  much  more  extended  and  clear  than  those  observable  in 
a  spectroscope,  however  powerful.  The  concave  plates  employed 
by  Professor  Rowland  were  made  by  Mr.  John  A.  Brashear  of 
Allegheny,  Pennsylvania. 

Measurement  is  greatly  indebted  to  accurate  means  of  enlarging 
the  images  of  objects  as  viewed  in  the  telescope  or  the  microscope. 
Glass  grinding  tools  are  to-day  so  exquisitely  contoured  that  a  lens 
forty-two  inches  in  breadth  shows  the  image  of  a  star  as  an  im- 
measurable dot.  It  was  in  pressing  together  two  lenses  of  very 
large  and  known  radius  that  Newton  measured  the  lengths  of 
light-waves.  With  homogeneous  rays,  such  as  those  of  yellow 
light,  the  successive  rings  of  light  and  darkness  marked  the 


Two  lenses  as  pressed  together  by  Newton. 

points  at  which  the  intervals  between  his  lenses  were  equal  to 
half  a  light-vibration  or  any  multiple  thereof.  Measuring  these 
intervals,  by  noting  their  distances  from  the  common  centre  of 
his  lenses,  he  found  the  wave-length  of  the  particular  light  he 
was  studying. 


238 


MEASUREMENT 


Intel-changeability 
Old  and  New. 


The  cheap  duplication  of  products,  so  wonderfully  expanded 
of  late  years,  had  its  germ  long  before  the  Christian  era,  when  in 
Babylonia  a  builder  first  made  bricks  in  a  mold, 
and  took  care  bJ  careful  measurement  to  keep 
to  uniform  dimensions  in  his  output.     Because 
any  brick  matched  any  other  from  the  same 
mold,  he  introduced  a  new  beauty  and  regularity  in  architecture, 

he  made  it  easy  to  extend 
or  repair  a  wall,  a  gate- 
way, a  battlement.  So  it 
was  afterward  with  the 
tiles,  also  made  in  molds, 
which  were  laid  as  floors 
or  roofs  ;  and  the  piping, 
likewise  molded,  for  water- 
supply  or  drainage.  To- 
day when  a  housekeeper 
replaces  her  worn-out 
stove-linings,  and  a  printer 
increases  his  stock  of  type, 
they  enjoy  a  direct  in- 
heritance from  the  first 
molders  of  bricks  and  tiles, 
cups  and  bowls.  In  a  modern  factory  vast  sums  are  expended  in 
producing  the  original  patterns,  molded  or  copied  perhaps  ten 
million  times,  so  that  their  cost,  in  so  far  as  represented  in  each 
manufactured  hook  or  lever,  is  next  to  nothing.  Much  expense, 
also,  is  entailed  in  making  the  jigs  which  guide  the  tools  used  in 
lathes  or  milling  machines  to  turn  out  the  cases  of  voltmeters,  or 
a  complicated  valve-seat.  A  jig  may  cost  a  hundred  dollars  and 
its  use  may  require  rare  steadiness  of  hand,  the  utmost  keenness 
of  eye;  all  the  while  the  operator's  wife,  at  home,  avails  herself 
of  an  aid  based  oh  the  very  same  principle.  What  else  is  the 
paper  pattern  according  to  which  she  cuts  out  a  collar,  an  apron. 
a  baby's  bib? 

In  machinery  the  first  introduction  of  an  interchangeability  of 
parts  was  by  General  Gribeauval,  in  the  French  artillery  service, 
about  1765.  He  reduced  gun-carriages  to  classes,  and  so  arranged 


Newton's  rings  as  produced  in 
yellow  light. 


STANDARDIZED  MANUFACTURES  239 

many  of  their  parts  that  they  could  be  applied  to  any  carriage  of 
the  class  for  which  they  were  made.    These  parts  were  stamped, 
not  forged.     The  next  step 
in  this  direction  was  taken  in 
America  and,  as  in  France,  its 

aim  was  to  improve  instru-         /  o    C    C    O    O 
ments  of  war.    Eli  Whitney, 
famous    as   the   inventor   of  Flat  jig,  or  guide, 

the    cotton    gin,    secured    a 

contract  from  the  United  States  Government  for  10,000  firearms. 
These  he  manufactured  almost  wholly  by  stamping.  He  introduced 
machinery  for  shaping  and,  as  far  as  then  feasible,  the  finishing 
of  each  part.  He  also  employed  a  system  of  gauges,  by  which  uni- 
formity of  construction  was  assured  for  every  gun  produced. 
Next  came  J.  H.  Hall,  of  .Harper's  Ferry,  Virginia,  who  in  1818 
made  every  similar  part  of  a  gun  of  such  size  and  shape  as  to  suit 
any  other  gun,  improving  some  details  of  importance. 

The  modern  designer  of  tools,  implements  and  machines  takes 
care  that  the  parts  upon  which  wear  chiefly  comes  are  easily  re- 
movable so  as  to  be  cheaply  replaced.  A  worn  out  plowshare  is 
renewed  for  a  dollar  or  two,  keeping  the  plow  as  a  whole  sub- 
stantially new.  Should  the  pinion  of  a  watch  be  destroyed  by 
accident,  it  is  duplicated  from  Waltham  or  Elgin  for  a  few  cents. 

To-day  rods,  wires,  screws,  bolts,  tubes,  nails,  sheets  of  metal, 
a/e  made  in  standard  sizes.  Much  the  same  is  true  of  rails  for 
railroads,  girders,  eye-bars  for  bridges,  and  the  like.  Thus  the 
product  of  any  factory  or  mill  may  be  used  to  piece  out  or  to  repair 
work  turned  out  by  any  other  similar  concern.  Yet  more,  if  a 
subway  or  a  tunnel  is  to  be  buijt  in  a  hurry,  two  or  more  steel- 
works may  co-operate  in  furnishing  beams,  columns,  or  aught 
else,  with  no  departure  from  ordinary  gauges.  Steel  works  in 
Pennsylvania  have  produced  every  detail  for  a  bridge  erected  in 
Africa,  a  factory  in  Germanv,  a  stamp  mill  in  Canada.  At  the 
World's  Congress  of  electricians  held  in  Chicago  in  1893,  units 
were  adopted  as  international  standards,  a  noteworthy  step  toward 
adopting  universal  standards  in  all  branches  of  engineering.  Here 
progress  is  to  some  extent  held  back  by  firms  and  corporations 
that  produce  patterns  not  always  worthy  of  defence.  Standard 


240  MEASUREMENT 

forms  and  dimensions,  especially  in  manufactures  for  a  world- 
market,  are  only  decided  upon  after  thorough  discussion,  so  that 
they  are  judiciously  chosen.  Among  feasible  shapes  and  sizes  for 
rails,  columns,  girders,  and  the  rest,  one  is  usually  best,  or  a  few 
are  best.  Why  not  exhaust  every  reasonable  means  of  ascertain- 
ing which  these  are  for  specific  tasks  that  they  may  be  freely 
chosen?  Then  if  individuality  prefers  its  own  different  designs, 
let  it  do  so  knowing  what  the  indulgence  costs. 

Measurements  may  be  conducted  in  the  strict  spirit  of  scientific 

research,  not  immediately  directed  to  industrial  ends.     Methods 

thus    perfected    are    more    and    more    being 

A  Test  Shows        adopted  for  large  questions  of  industry.     Let 

iJI°1C^Cret?       an  example  be  presented  from  the  field,  briefly 

Maybe  Cheaply  f          .  * 

Strengthened.        touched  upon  in  this  book,  of  concrete  as  a 

material  for  the  builder.  Says  Mr.  C.  H.  Um- 
stead  of  Washington,  Pennsylvania  : — 

"Many  thousands  of  tons  of  the  finer  grades  of  stones  from  the 
crushers  all  over  the  country  are  rejected  by  engineers  for  use  in 
concrete  foundations  and  walls,  sand  being  preferred  at  greatly 
increased  cost.  I  prepared  seventy-two  three-inch  cubes  with 
quartz  sand  and  with  varying  proportions  of  crushed  stone  which 
was  going  to  the  dump  as  unfit  for  foundation  work,  and  sub- 
mitted them  to  crushing  tests  at  periods  of  fourteen  and  twenty- 
eight  days.  The  proportion  of  Portland  cement  was  constant." 

From  Mr.  Umstead's  table  of  results  the  following  figures  are 
chosen ;  on  comparing  those  for  the  first  and  t'.iird  cubes  they  show 
that 'a  gain  in  strength  of  forty-three  per  cent,  followed  upon 
using  six  pounds  of  crusher  refuse  instead  of  five  and  one  half 
pounds  of  sand.  . 


Portland  Crushed  Compressive  Strain 

Sand  Cement  Water  Refuse  14  Days  28  Days 

8.5  Ibs.          4.5  Ibs.          I  lb.  none  2850  Ibs.  per  sq.  in.          3670 

6      "  4-5  "  lib.  3  Ibs.  3120    "     "       "  5050 

3      "  4.5  "  1-125  Ibs  6   "  3620    "     "       "  5250 

So  much  for  the  value  of  a  test  in  the  improvement  of  an  im- 
portant manufacture. 


BUYING  ONLY  ON  TESTS  241 

Mr.  Umstead's  full  report  appeared  in  1903,  in  the  third  volume 
of  bulletins  published  by  the  American  Society  for  Testing  Mate- 
rials. This  Society,  whose  secretary  is  Professor  Edgar  Marburg 
of  the  University  of  Pennsylvania,  Philadelphia,  is  affiliated  with 
the  International  Association  for  Testing  Materials,  one  of  the 
most  important  agencies  in  existence  for  providing  the  engineer 
with  trustworthy  data. 

Measurement  industrially  is  taking  on  a  new  and  rapidly  ex- 
tending scope.    It  is  of  great  moment  that  a  railroad  or  a  steam- 
ship, a  factory  or  a  mill,  should  be  built  of  the 
best  materials  in  the  most  economical  way,  that      industrial  Us»s 
it  should  be  equipped  with  the  most  efficient      of  Measurement, 
boilers,  engines,  machines,  and  lamps :  in  effect, 
that  every  dollar  be  expended  for  the  utmost  possible  value. 

At  Altoona  the  Pennsylvania  Railroad  Company  has  a  labora- 
tory for  testing  the  materials  which  go  into  its  roadbed,  bridges, 
tracks,  rolling  stock,  buildings,  telegraph,  and  signal  systems. 
Every  gallon  of  oil,  each  incandescent  lamp,  car  axle,  or  boiler 
plate  accepted  by  the  Company  must  pass  a  due  test  in  a  con- 
tinuous series  of  competitive  examinations.  The  huge  scale  of 
such  a  Company's  purchases,  the  strains  placed  upon  its  equip- 
ment by  a  service  growing  in  extent  and  in  speed,  make  this 
course  indispensable.  Take  another  case,  this  time  in  New  York, 
at  the  power-house  of  the  Interborough  Company  in  West  59th 
Street.  There  every  day  a  fair  sample  of  the  coal  brought  to  the 
dock  is  burned,  and  its  heat-units  ascertained  as  a  basis  for  pay- 
ment. With  a  consumption  which  may  rise  to  1500  tons  a  day 
this  precaution  is  obligatory.1 

1  The  United  States  Geological  Survey,  Washington,  D.  C,  in  1906  pub- 
lished a  report  on  the  coal  testing  plant  at  the  Exposition,  St.  Louis,  Mo., 
1004.  Part  I,  Field  work,  classification  of  coals,  chemical  work.  Part  II, 
Boiler  tests.  Part  III,  Producer-gas,  coking,  briquetting,  and  washing  tests. 
This  report,  with  elaborate  tables  and  many  illustrations,  is  of  great  value. 

The  Pennsylvania  R.  R.  Co.,  Philadelphia,  in  1905  published  a  large 
and  handsomely  illustrated  volume,  "Locomotive  tests  and  exhibits,  St. 
Louis,  1904."  $5.00.  The  locomotives  represented  the  best  American 
practice  of  1904.  Every  detail  of  construction  and  operation  is  given  in 
the  most  instructive  manner. 

The  Company  is  continuing  these  tests  of  locomotives  at  Altoona,  Pa. 


242  MEASUREMENT 

On  quite  other  lines,  equally  important,  the  ascertainment  of 
values  proceeds  at  laboratories  thoroughly  organized  for  the  pur- 
pose by  staffs  at  the  service  of  the  public.  In  the  United  States 
the  first  in  rank  of  such  laboratories  are  grouped  at  the  Bureau 
of  Standards  in  Washington.  At  leading  universities  and  techno- 
logical institutes  throughout  the  Union  are  other  laboratories  well 
equipped  for  chemical,  physical,  and  engineering  tests.  At  the 
Massachusetts  Institute  of  Technology  in  Boston,  for  example,  is 
an  Emery  testing  apparatus  for  making  compression  tests  of 
specimens  up  to  eighteen  feet  in  length,  for  tension  specimens  up 
to  thirteen  feet.  In  Europe  analogous  institutions  are  supple- 
mented by  the  Board  of  Trade  Laboratories  in  London,  the  Labo- 
ratoire  Central  in  Paris,  the  Reichsanstalt  in  Berlin.  The  Electrical 
Testing  Laboratories,  a  joint-stock  concern,  has  been  established 
in  New  York,  at  Eightieth  Street  and  East  End  Avenue,  for 
similar  tasks  in  so  far  as  they  come  within  the  electrical  field.  Its 
direction  in  ability  and  character  is  authoritative.  Here  is  some  of 
the  best  apparatus  in  the  world  for  tests  of  the  permeability  of 
magnet  iron,  of  the  light  from  incandescent,  arc,  or  other  electric 
lamps,  of  gas-burners  and  mantles,  of  the  extent  to  which  re- 
flectors and  globes  fulfil  their  purpose,  and  so  on. 

It  is  altogether  probable  that  this  concern  will  be  copied  in 
every  other  large  city  of  the  Union.  When  an  electrical  plant  is 
installed  it  is  not  enough  that  the  specifications  be  drawn  with 
care,  it  is  necessary  that  verifications  of  quality  follow  upon  de- 
livery of  dynamos,  motors,  lamps,  and  all  else.  Tests  should  be 
continuous :  let  us  suppose  that  for  a  specific  task  of  illumination 
Nernst  lamps  are  selected.  All  very  well,  but  the  question  is, 
What  quality  has  each  lamp?  Buyers  in  cases  of  this  kind  are 
more  and  more  referring  rival  manufactures  to  tests  which  settle, 
as  in  a  court  of  final  appeal,  differences  upon  which  they  them- 
selves are  incompetent  to  pass.  Not  only  in  sale  but  in  production 
these  tests  are  of  the  first  importance.  If  a  copper  refinery  turns 
out  from  the  same  batch  of  crude  metal  two  samples  which  vary 
by  a  thousandth  in  electrical  conductivity,  it  is  worth  while  know- 
ing every  detail  which  may  explain  how  the  better  sample  was 
produced.  So  likewise  in  the  drawing  of  wire,  the  alloying  of 
lead  with  other  metals  for  anti-friction  bearings,  and  so  on. 


MODERNIZING  A  PLANT  243 

It  is  altogether  likely  that  recourse  to  authoritative  tests  will 
soon  become  general.  Before  many  years  elapse  we  may  see 
private  and  public  laboratories  multiplied  for  the  comparison  of 
building  and  road-making  materials,  fuel,  boilers,  engines,  ma- 
chines, lubricants,  finished  goods  of  all  kinds.  In  the  textile  in- 
dustry, for  instance,  much  is  said  about  the  waste  entailed  in  mix- 
ing sound  wool  with  shoddy,  long  staple  cotton  with  short  inferior 
brands.  Let  pure  and  adulterated  fabrics  be  compared  in  re- 
sistance to  wear,  and  let  the  effects  of  scouring,  bleaching,  dye- 
ing, and  mechanical  washing  be  measured.  In  another  field  Pro- 
fessor W.  O.  Atwater  has  done  much  to  ascertain  the  nourishing 
value  of  foods :  his  labors  might  well  be  extended  full  circle,  not 
omitting  tests  of  popular  medicaments  and  common  drugs. 

To-day  engineers  of  mark  are  engaged  not  only  to  plan  a 
power-house,  a  flour  mill,  a  steel  works  or  other  vast  installation, 
but  also  to  examine  industrial  plants  estab- 
lished long  ago  and  enlarged  from  time  to  Expert  Planning 
time  in  an  unsystematic  way.  Armed  with  and  Reform. 
scales,  pressure-gauges,  indicators,  voltmeters, 
they  ascertain  the  cost  of  a  horse-power-hour,  of  making  a  pound 
of  flour,  copper  wire,  or  aught  else.  They  note  how  speeds  may 
be  heightened  with  profit,  as  by  using  suitable  brands  of  high- 
speed steels.  They  suggest  how  a  pattern  may  be  adopted  in  the 
foundry  which  will  lessen  machining;  how  by-products  now 
thrown  away  may  be  turned  to  account.  They  point  out  how 
quality  may  be  improved  by  the  adoption  of  new  machines  which 
may,  furthermore,  demand  unskilled  instead  of  skilled  attend- 
ance. They  may  advise,  from  a  wide  outlook  on  the  whole  field 
of  American  experience,  a  method  for  equalizing  output  through- 
out the  day  and  throughout  the  year,  as  when  a  central-lighting 
station  sells  current  at  a  large  discount  during  the  hours  when 
no  lamps  are  aglow,  so  that  ice  may  be  manufactured  at  such 
periods,  or  batteries  restored  for  use  in  automobiles  and  motor- 
boats.  Mr.  Wilson  S.  Howell,  of  New  York,  a  few  years  ago 
became  convinced  that  a  neglected  branch  of  economy  in  central 
lighting  stations  was  the  maintaining  a  uniform  voltage.  He  suc- 
ceeded in  reducing  fluctuations  in  many  plants  to  the  unexampled 
figure  of  four  per  cent.  The  result  was  that  he  lowered  the  cur- 


244  MEASUREMENT 

rent  necessary  for  an  Edison  lamp  from  3.6  watts  to  3.1  watts  per 
candle-power,  a  saving  of  one  seventh.  Mr.  M.  K.  Eyre,  another 
well-known  engineer,  once  took  charge  of  a  lamp  factory  in  Ohio. 
In  four  months  he  had  reduced  cost  forty  per  cent,  while  pro- 
ducing a  lamp  of  the  best  quality.  An  electric  lighting  and  power 
property  which  for  years  had  been  unprofitable  was  placed  in  the 
hands  of  Messrs.  J.  G.  White  &  Company  of  New  York,  an  en- 
gineering firm  of  the  first  rank.  Within  a  few  months  the  prop- 
erty was  earning  a  substantial  surplus ;  the  ratio  of  operating  to 
gross  earnings  was  reduced  about  thirty  per  cent.,  and  the  gross 
earnings  showed  an  increase  over  corresponding  months  of  the 
previous  year  of  nearly  forty  per  cent.  Economies  quite  as  strik- 
ing have  been  effected  by  the  firm  of  Messrs.  Dodge  &  Day  of 
Philadelphia.  On  request  investigators  of  this  stamp,  whose  aim 
is  to  abolish  waste  and  promote  efficiency,  go  beyond  mechanical 
and  engineering  details.  They  may  point  out  how  needed  work- 
ing capital  may  be  obtained,  how  best  to  extend  sales,  and  pos- 
sibly how  an  economical  consolidation  with  other  similar  plants 
may  be  effected.  Almost  invariably  it  is  found  imperative  to  re- 
cast the  bookkeeping  methods,  especially  with  regard  to  ascer- 
taining the  cost  of  production  in  each  department.  Drawing 
upon  experience  recommendations  may  follow  as  to  premium 
plans  of  paying  wages,  and  other  methods  of  identifying  the 
interests  of  employers  and  employed.1  Approved  schemes  for  the 
comfort  and  welfare  of  work  people  are  also  suggested  by  coun- 
sellors thoroughly  aware  that  contentment  is  great  gain,  that 
pure  air,  good  light,  and  the  utmost  feasible  safety,  contribute  to 
the  balance  sheet  not  less  than  the  quickest  lathe  tools  or  the  best 
wound  dynamo. 

JMr.  T.  S.  Halsey  is  a  contributor  to  "Trade  Unionism  and  Labor 
Problems,"  published  by  Ginn  &  Co.,  Boston,  1905.  He  recites  (p.  284) 
how  a  corporation  had  manufactured  a  product  again  and  again.  Both 
workmen  and  foreman  were  positive  that  the  working  time  was  at  the 
minimum.  The  premium  plan  of  payment  was  introduced,  with  a  reduc- 
tion in  time  of  41  per  cent,  as  the  result. 


CHAPTER  XVIII 
NATURE  AS  TEACHER 

Forces  take  paths  of  least  resistance  .  .  .  Accessibility  decides  where 
cities  shall  arise  .  .  .  Plants  display  engineering  principles  in  structure. 
Lessons  from  the  human  heart,  eye,  bones,  muscles,  and  nerves  .  .  . 
What  nature  has  done,  art  may  imitate, — in  the  separation  of  oxygen 
from  air,  in  flight,  in  producing  light,  in  converting  heat  into  work  .  .  . 
Lessons  from  lower  animals  ...  A  hammer-using  wasp 

BEYOND  their  unending  study  of  forms  and  properties,  their 
constant  weighing  and  measuring,  the  inventor  and  his 
twin-brother,  the  discoverer,  have  a  gainful  province  which  now 
for  a  little  space  will  engage  our  attention.  This  province  is 
nothing  else  than  Nature,  which  begins  by  offering  primitive  man 
stones  for  hammers,  arrowheads,  knives ;  sticks  to  serve  as  clubs, 
paddles,  harrows  or  tent-poles.  We  may  well  believe  that  the 
lowest  savages  have  always  exercised  some  degree  of  choice  even 
here;  it  would  be  the  soundest  and  sharpest  stone  that  they 
picked  up  when  a  rude  axe  was  needed.  Should  only  blunt  stones 
be  found,  then  in  giving  one  of  them  an  edge  was  taken  a  first 
step  in  art,  rewarded  with  a  tool  as  good  as  the  axe  found  ready 
to  hand  in  some  earlier  quest.  Nature  is  not  only  a  giver  of  much 
besides  stones  and  sticks,  she  is  virtually  a  great  contriver  whose 
feats  may  incite  the  inventor  to  reach  her  goals  if  he  can ;  his 
path  will  probably  differ  widely  enough  from  hers  as  he  arrives 
at  success. 

When  one  drop  of  rain  meets  another,  and  they  join  them- 
selves to  thousands  more  on  the  crest  of  a  hill,  they  need  no 
guide  posts  to  show  them  the  easiest  course  to 
the  valley.    They  simply  take  it  under  the  quiet  Forces 

pull  of  gravity.  When  a  bolt  of  lightning  darts       Easiest  Paths 
across  the  sky,  its  lines,  chaotic  as  they  seem, 
are  just  the  paths  where  the  electric  pulses  find  least  obstruction. 
If  a  volcano,  which  has  boiled  and  throbbed  for  ages,  at  last 

245 


246  NATURE  AS  TEACHER 

opens  a  chasm  on  a.  hapless  shore,  as  that  of  Martinique,  we  may 
be  sure  that  at  that  point  and  nowhere  else  the  mighty  caldron's 
lid  was  lightest.  A  cavern  in  Kentucky,  or  Virginia,  slowly 
broadening  and  deepening  through  uncounted  rills  which  dissolve 
its  limy  walls,  comes  at  last  to  utter  collapse :  the  breach  marking 
exactly  where  an  ounce  too  much  pressed  the  roof  at  its  frailest 
seam.  In  these  cases  as  in  all  others,  however  complex,  matter 
moves  inevitably  in  the  path  of  least  resistance.  To  imitate  that 
economy  of  effort  is  from  first  to  last  the  inventor's  task. 

Rains,  winds  and  frosts,  in  their  sculpture  of  the  earth  have 
each  taken  the  easiest  course;  in  so  doing  they  have  incidentally 

marked  out  the  best  paths  for  human  feet,  have 
Cities  and  Roads,  pointed  to  the  best  sites  for  the  homes  of  men. 

The  stresses  of  defence  may  rear  a  pueblo,  on 
the  peak  of  a  perpendicular  cliff  in  New  Mexico,  but  Paris  and 
London,  like  Rome,  must  have  all  roads  leading  to  their  gates; 
and  the  easier  and  shorter  these  roads,  the  bigger  and  stronger 
the  city  will  become.  Where  New  York,  Montreal,  Chicago,  and 
Pittsburg  now  stand,  the  Indians  long  ago  had  the  wit  to  found 
goodly  settlements.  They  knew,  as  well  as  their  white  succes- 
sors, the  advantages  of  paths  readily  traversed,  and  no  longer 
than  need  be.  In  this  regard  there  was  an  instructive  contrast  at 
the  outset  of  railroad  building  in  England.  A  leading  engineer, 
who  planned  some  of  the  earliest  English  railways,  had  strong 
mathematical  prepossessions :  he  endeavored  to  join  the  terminals 
of  his  routes  by  lines  as  nearly  straight  as  he  could.  George 
Stephenson,  for  his  part,  had  no  mathematical  warp  of  any  kind, 
but  instead  much  sound  sense;  his  lines  followed  the  courses  of 
rivers  and  valleys,  and  kept,  as  much  as  might  be,  to  the  chief 
indentations  of  the  sea.  His  roads  deviated  a  good  deal  from 
straightness,  but  they  did  so  profitably;  whereas  the  lines  of  his 
academic  rival,  disrespecting  the  hints  and  indications  of  nature, 
were  much  less  gratifying  from  an  investor's  point  of  view.  If 
a  traveler  takes  the  New  York  Central  and  Hudson  River  Rail- 
road from  New  York  to  Buffalo  he  goes  north  for  143  miles,  to 
Albany,  before  he  begins  to  travel  westward  at  all.  Yet  this 
line,  keeping  as  it  does  to  the  well-peopled  levels  of  the  Hudson 
and  Mohawk  Valleys  and  serving  their  succession  of  cities, 


VEGETATION 


247 


towns,  and  villages,  enjoys  the  best  business,  and  makes  better 
time  between  its  terminals  than  any  rival  route,  because  it  passes 
around  instead  of  over  its  hills  and  mountains.  By  way  of  con- 
trast we  turn  to  the  railroad  map  of  Russia  and  observe  how 
Moscow  and  St.  Petersburg  are  joined  by  a  line  which  follows 
the  road  which  it  is  said  that  Peter  the  Great,  with  military 
exigencies  in  view,  laid  down  with  a  pencil  and  ruler. 

If  the  engineer  has  many  a  golden  hint  spread  before  him  in 
the  hills  and  dales,  the  streams  and  oceans  of  the  world,  not  less 
fruitful  is  the  study  of  what  takes  place  just 
beneath  the  surface  of  the  earth  where  the 
roots  of  grain  and  shrub,  reed  and  tree,  take 
life  and  form.  Plant  a  kernel  of  wheat  in  the 
ground  and  note  how  its  rootlets  pierce  the  soil,  extending  always 
from  the  tip.  They  need  no  gardener  or  botanist  to  bid  them 


Engineering 
Principles  in 
Vegetation. 


Deciduous  cypress,  Taxodium  distichum. 

lengthen  and  thicken  where  food  chiefly  abounds.  In  an  arid 
plain  of  Arizona  a  vine,  in  ground  parched  and  dry,  goes  down- 
ward so  far,  and  spreads  its  fibrils  so  much  abroad,  as  soon  to 


248 


NATURE  AS  TEACHER 


Deciduous  cypress,  hypothetical 
diagram. 


show  ten  times  as  much  growth  below  the  drifting  sands  as  above 
them.  In  fertile,  well-watered  soil  the  same  vine  descends  less 

than  half  as  far,  and  yet  with 
more  gain.  A  bald  cypress 
in  a  swamp  of  Florida  re- 
sponds to  different  sur- 
roundings with  equal  profit. 
Finding  its  food  near  the 
surface  its  roots  take  hori- 
zontal lines,  at  no  great 
depth  in  the  soil.  Every 
wind  that  stirs  these  roots 
but  promotes  their  thrift  and 
strengthens  their  anchorage. 
A  wealth  of  sustenance 

floats  in  the  swamp  water.  In  seizing  it  and  being  thereby  fed, 
the  roots  develop  "knees";  these  brace  the  tree  so  firmly  against 
tempests  as  to  win  admiration  from  the  engineer.  When  the 
progeny  of  this  cypress  grow  on  well-drained  land,  the  knees 
do  not  appear,  while  the  roots  within-  a  narrowed  area  strike  deep. 
Thus  simply  in  doing  what  its  surroundings  incite  it  to  do,  the 
tree  acts  as  if  it  had  intelligence,  as  if  it  consciously  saw  and 
chose  what  would  do  it  most  good. 

Lumbermen  in  the  North  observe  much  the  same  responsive- 
ness. In  a  grove  of  pines  they  see  that  the  trees  which  stand  close 
together  are  tall  and  cylindrical.  When  all  the  pines  but  one  in  a 
cluster  are  cut  down,  that  one  will  speedily  thicken  the  lower  part 
of  its  trunk  by  virtue  of  the  increased  action  of  the  winds,  just 
as  a  muscle  thickens  by  exercise. 

So  also  is  there  responsiveness  when  we  look  upon  the  life  of 
plants  in  the  large.  As  the  traits  of  a  shrub  or  tree  are  borne 
into  its  seed  many  a  thousand  impulses  are 
merged  and  mingled.  Little  wonder  that  their 
delicate  accord  and  poise  should  be  slightly 
different  from  those  of  the  seeds  from  which  the  parents  sprang. 
Let  us  suppose  these  parents  to  be  cactuses,  and  that  the  offspring 
displays  an  unusually  broad  stem,  of  less  surface  comparatively 
than  any  other  plant  in  its  group.  In  a  soil  seldom  refreshed  by 


The  Gain  of 
Responsiveness. 


UNWITTING  IMITATION  249 

rain,  this  cactus  has  the  best  foothold  and  maintains  it  with  most 
vigor.  Sandstorms  which  kill  brethren  less  sturdy,  strike  it  in 
vain,  so  that  its  kind  is  multiplied.  Wherever  such  a  new  char- 
acter as  this  gives  a  plant  an  advantage,  it  holds  the  field  while  its 
neighbors  perish.  Thus  arises  a  high  premium  on  every  useful 
variation,  be  it  in  new  stockiness  of  form,  an  acridity  which  repels 
vermin,  or  a  strength  which  readily  makes  a  way  through  sun- 
baked earth.  Hence  such  new  traits  are,  as  it  were,  seized  upon 
and  become  points  of  departure  for  new  varieties,  and  in  the 
fullness  of  time,  for  new  species.  About  a  hundred  years  ago 
a  gardener  imagined  a  tuberous  begonia,  and  then  proceeded  step 
by  step  toward  its  creation  by  breeding  from  every  flower  that 
varied  in  the  direction  he  desired.  This  man,  and  all  his  kindred 
who  have  added  to  our  riches  in  cultivated  blooms,  have  no  more 
than  copied  the  modes  of  nature  which,  at  the  end  of  ages,  bestows 
as  free  gifts  every  wildflower  of  the  field  and  hedgerow.  If  the 
botanist  of  to-day  is  the  master  of  a  plastic  art,  so  is  the  cattle- 
breeder  who  chalks  on  a  barn-door  the  outline  of  a  beeve  he 
wishes  to  produce,  and  then  straightway  plans  the  matings  which 
issue  in  the  animal  he  has  pictured.  Artificial  selection,  such  as 
this,  is  after  all  only  imitation  of  that  natural  selection  which  has 
derived  the  horse  from  a  progenitor  little  larger  than  a  fox,  in 
response,  age  after  age,  to  changing  food,  climate,  enemies,  and 
the  needs  of  his  human  master. 

Fields  remote  from  those  of  the  naturalist  are  just  as  instruc- 
tive.    The  inventor  sets  before  himself  an  end  with  conscious 
purpose,  and  then   seeks  means  to  reach  that 
end,  but  at  best  his  methods  may  be  wasteful  Scope  for 

,    .  .  .  Imitation. 

and  imperfect.  Nature,  with  unhasting  tread, 
acting  simply  through  the  qualities  inherent  in  her  materials, 
through  their  singular  powers  of  combination,  of  mutual  adapt- 
ability, shows  the  discoverer  results  which  to  understand  even  in 
small  measure  tax  his  keenest  wit,  or  displays  to  him  structures 
at  times  beyond  his  skill  to  dissect,  much  less  to  imitate.  Me- 
chanic art,  indeed,  is  for  the  most  part  but  a  copy  of  nature,  as 
when  the  builder  repeats  the  mode  in  which  rocks  are  found 
in  caves,  in  ridges  at  the  verge  of  a  cliff,  or  in  the  stratifications 
which  underlie  a  county,  all  conducing  to  permanence  of  form,  to 


250  NATURE   AS    TEACHER 

resistance  against  abrading  sand  or  dissolving  waters.  What 
ensures  the  stability  of  a  lighthouse  but  its  repetition  of  a  tree- 
trunk  in  its  contour  ?  Engines  and  machines  recall  the  animal 
body,  grinding  ore  much  as  teeth  grind  nuts,  lifting  water  as  the 
heart  pumps  blood  through  artery  and  vein,  and  repeating  in 
mechanism  of  brass  and  steel  the  dexterity  of  fingers,  the  blows 
of  fists.  When  an  inventor  builds  an  engine  to  drive  a  huge  ship 
across  the  sea,  he  has  created  a  motor  vastly  larger  than  his  own 
frame,  but  much  inferior  in  economy.  At  a  temperature  little 
higher  than  that  of  a  summer  breeze  the  human  mechanism  trans- 
mutes the  energy  of  fuel  into  mechanical  toil :  for  the  same  duty, 
less  efficiently  discharged,  the  steam  engine  demands  a  blaze  al- 
most fierce  enough  to  melt  grate  bars  of  iron. 

Heat  is  costly,  so  that  its  conservation  is  an  art  worth  knowing. 
In  the  ashes  strewn  and  piled  on  burning  lava  nature  long  ago 
told  us  how  heat  may  be  secured  against  dissipation.  Other  of 
her  garments,  as  hair  and  fur,  obstruct  the  escape  of  heat  in  a 
remarkable  degree,  and  so  does  bark,  especially  when  loosely 
coherent  as  in  the  cork  tree.  Feathers  are  also  excellent  retainers 
of  heat,  and  have  thereby  so  much  profited  their  wearers,  that 
Ernest  Ingersoll  holds  that  the  development  of  feathers  has  had 
much  to  do  with  advancing  birds  far  above  their  lowly  cousins, 
the  reptiles  clad  in  a  scaly, vesture. 

As  we  look  back  upon  the  past  from  the  vantage  ground  of 
modern  insight  we  see  that  men  of  the  loftiest  powers  could  be 

blind  to  intimations  now  plain  and  clear.   Many 
Strength  of  the       a  time  haye  Designers  and  inventors  paralleled, 

without  knowing  it,  some  structure  of  nature 
often  seen  but  never  really  observed.  All  the  variety  and  beauty 
of  the  Greek  orders  of  architecture  failed  to  include  the  arch; 
yet  the  contour  of  every  architect's  own  skull  was  the  while  dis- 
playing an  arched  form  which  could  lend  to  temple  and  palace 
new  strength  as  well  as  grace.  The  skeleton  of  the  foot  reveals 
in  the  instep  an  arch  of  tarsal  and  metatarsal  bones,  with  all  the 
springiness  which  their  possessor  may  confer  upon  a  composite 
arch  of  wood  or  steel.  Modern  builders,  whether  wittingly  or 
not,  have  taken  a  leaf  from  the  book  of  nature  in  rearing  their 
tallest  structures  with  hollow  cylinders  of  steel.  What  is  this 


ENSURING  STRENGTH 


251 


but  borrowing  the  form  of  the  reed,  the  bamboo,  a  thousand 
varieties  of  stalk,  one  of  the  strongest  shapes  in  which  supporting 
material  can  be  disposed?  Pass  a  knife  across  a  blade  of  pipe  or 
moor  grass  and  you  will  find  a  hollow  cylinder  stayed  by  but- 
tresses numbering  nearly  a  score.  More  elaborate  and  even  more 


Section  of  pipe  or 
moor  grass. 


Cross-section  of  bul- 
rush, Scirpus  lacustris. 


gainful  is  the  way  in  which  tissue  grows  in  the  columns  of  dead- 
nettles  and  bulrushes.  The  bones  in  one's  arms  and  legs  resemble 
the  hollow  cylinders  of  which  these  stalks  show  instructive 
variations,  so  that  without  going  beyond  his  own  frame  the  de- 
signer could  long  ago  have  learned  a  golden  lesson.  How  bone 
is  joined  to  bone  is  scarcely  less  remarkable,  as  in  the  braces  of 
the  thigh  bone  as  it  joins  the  trunk.  As  bones  move  upon  each 
other  all  shock  is  prevented  by  a  highly  elastic  cushion :  the 
springs  of  vehicles,  the  buffers  of  railroad  trains,  but  repeat  the 
cartilages  in  the  joints  of  their  inventors. 

In  the  theodolite  and  sextant,  in  the  geometric  lathe  of  the 
bank-note  engraver,  are  ball-and-socket  joints  allowing  motion  in 
any  plane.  Equally  free  in  their  movements  are  the  shoulder  and 
hip  joints,  while  their  surfaces  are  lubricated  by  a  delicate  syno- 
vial  fluid  supplied  just  as  it  is  wanted.  When  pumps  first  re- 
ceived valves  to  direct  their  flow  in  one  direction,  their  inventor 
was  no  doubt  gratified  at  his  skill.  In  the  heart  within  his  own 
breast,  in  his  veins  and  arteries,  were  simple  valves  engaged  in  a 
similar  task  as  they  directed  the  currents  of  his  blood.  In  pumps 
such  as  are  common  in  farm-yards,  the  action  is  jerk^y,  the  stream 
flowing  and  ebbing  from  moment  to  moment  as  the  arm  rises  and 


252 


NATURE  AS  TEACHER 


falls.     The  tide  of  human  blood  would  have  the  same  uneven 
pulse  were  it  not  for  the  elasticity  of  its  arterial  walls.     Their 


Human  hip  joint  in  section.  From 
"The  Human  Body,"  by  H.  N.  Martin. 
Copyright,  Henry  Holt  &  Co.,  New 
York,  1884.  Reproduced  by  their  per- 


mission. 


Valves  of  veins. 

C,  a  capillary;  H, 
the  heart  end  of  the 
vessel.  From  "The 
Human  Body,"  by 
H.N.Martin.  Copy- 
right, 1884,  Henry 
Holt  &  Co.,  New 
York,  and  repro- 
duced by  their  per- 
mission. 


elasticity  serves  to  equalize  the  flow,  much  as  the  air  does  in 
large  chambers  on  pumps  for  mines  or  waterworks. 

Examination  of  the  heart  brings  out  a  principle  in  its  structure 
closely  paralleled  in  modern  invention.  Guns  of  old  were  cast 
or  forged  as  ordinary  columns  or  shafts  are 
to-day,  the  strength  of  the  metal  being  vir- 
tually uniform  throughout  when  the  guns  were 
at  rest  on  their  trunnions.  As  explosive 
charges  more  and  more  powerful  were  employed,  these  guns 
gave  way,  the  pressure  of  the  exploding  gases  stretching  the 
metal  at  the  bore  to  rupture,  before  the  outer  metal  could  add  its 
resistance.  A  modern  built-up  gun  is  made  up  of  a  series  of,  let 


The  Heart  and 

the  Built-up 

Gun. 


THE  HEART  253 

tis  say,  four  cylinders :  the  first,  of  comparatively  small  bore  and 
thickness,  is  innermost.  It  is  cooled  to  as  low  a  temperature  as 
possible,  when  a  second  cylinder  is  slipped  over  it  red-hot  to  form 
a  tight  fit.  Both  masses  of  metal  are  now  slowly  cooled,  when  a 
third  red-hot,  closely  fitting  cylinder  is  passed  over  them.  All 
three  united  masses  are  now  cooled,  when  the  fourth  and  widest 


Built-up  gun. 


cylinder  of  all,  red-hot,  is  passed  over  these  three  inner  tubes,  and 
the  whole  gun  is  allowed  gradually  to  fall  in  temperature.  When 
this  process  is  completed  the  inner  parts  of  the  gun,  by  virtue  of 
the  shrinkage  in  the  metal  as  it  cooled,  are  under  severe  com- 
pression, while  the  outer  parts  are  in  as  extreme  a  state  of  stretch 
or  tension.  When  such  a  gun  is  fired  its  inner  cylinders  oppose 
much  greater  resistance  to  the  outward  pressure  of  the  exploding 
gases  than  did  the  walls  of  the  old-time  guns.  The  strength  of 
the  old  guns  was  uniform  throughout  when  they  were  doing 
nothing,  and  very  far  from  uniform  at  the  instant  of  firing;  a 
built-up  gun,  on  the  contrary,  has  uniform  strength  in  its  every 
part  just  when  that  uniformity  is  wanted,  at  the  moment  of  ex- 
plosion. The  built-up  gun  therefore  uses  projectiles  vastly  heavier 
and  swifter  than  those  of  former  times.  Its  structure,  made  up 
of  cylinders  successively  shrunk  one  upon  another,  resembles 
that  of  the  heart,  whose  two  inner  parts  have  their  fibres  wound 
somewhat  like  balls  of  twine,  these  in  turn  being  tightly  com- 
pressed by  a  covering  of  other  fibres.  The  heart  has  to  resist  no 
such  explosive  force  as  arises  within  a  gun,  but  in  its  propulsion 
of  blood  through  the  arteries  and  veins  it  has  to  exert  great  pres- 
sure, with  no  rest  throughout  a  lifetime.  This  pressure  is  uni- 
formly distributed  throughout  the  muscular  tissue  by  a  structure 
which,  as  engineers  would  say,  has  its  outer  layers  in  tension  and 
its  inner  layers  in  compression.  During  twenty- four  hours  the 


254  NATURE  AS  TEACHER 

labor  of  an  average  human  heart  is  equal  to  lifting  two  hundred 
and  twenty  tons  one  foot  from  the  ground. 

What  building-up  does  to  strengthen  the  gun  has  been  re- 
peated in  the  case  of  the  circular  saw :  driven  at  a  high  speed  it 
becomes  so  highly  heated  at  its  periphery  that  the  resulting  ex- 
pansion may  crack  the  metal  in  pieces.  In  an  improved  method 
of  manufacture  the  saw  is  hammered  to  a  compression  which 
gradually  increases  from  rim  to  centre.  In  this  way  the  tendency 
of  the  periphery  to  fly  apart  is  withstood  by  the  compressive  forces 
at  the  central  portion  of  the  disc. 

This  ingenious  treatment  of  metal  for  guns  and  saws  reminds 
us  of  a  familiar  resource  in  carpentry,  illustrated  on  page  36.  An 
ordinary  book-shelf,  if  fairly  long  and  not  particularly  stout, 
bends  beneath  its  burden  and  may  at  last  slip  out  from  its  mortices 
and  fall  with  injury  to  its  books.  At  the  outset  this  is  prevented 
by  bending  the  shelf  to  convexity  on  its  upper  surface.  Then  a 
heavy  load  no  more  than  brings  the  shelf  to  straightness,  so  that 
the  books  remain  in  their  places  with  both  safety  and  sightliness. 
Here  a  principle  is  involved  worth  a  moment's  pause.  An  in- 
ventor asks,  What  effect  will  a  working  load  exert  which  it  is 
desirable  to  lessen  or  withstand?  He  gives  his  structure  a  form 
opposite  to  that  which  will  result  from  an  imposed  burden,  so 
that  when  at  work  his  structure,  a  shelf,  a  cylinder,  a  saw,  will 
assume  its  most  effective  shape. 

From  childhood  we  are  familiar  with  the  triangular  prisms  of 
glass  which  break  a  sunbeam  into  all  the  hues  of  the  rainbow.  A 
lens  is  a  prism  of  circular  form,  and  has, 
The  Eye  and  the  equally  with  an  ordinary  prism,  the  power  to 
Dollond  Lenses,  show  rays  of  all  colors.  This  was  for  a  long 
time  a  source  of  error  and  annoyance  in  tele- 
scopic images.  Sir  Isaac  Newton  from  some  rough  and  ready 
experiments  concluded  that  the  trouble  was  beyond  remedy,  yet 
all  the  while  his  own  eyeballs  were  transmitting  images  with  little 
or  no  vexatious  fringe  of  color.  Let  us  note  how  Dollond  set 
about  a  task  which  Newton  deemed  impossible.  He  knew,  what 
Newton  did  not  know,  that  crown  glass  disperses  or  scatters  light 
only  half  as  much  as  does  flint  glass,  so  he  united  a  lens  of  the 
one  to  a  lens  of  the  other,  and  obtained  a  refracted  or  bent  beam 


COLOR-FREE  LENSES 


255 


of  light  almost  unchanged  in  its  whiteness.  Of  course,  in  this 
combination  there  was  an  increased  thickness  of  glass,  but  its 
doubled  absorption  and  waste  of  light  was  a  small  drawback  com- 
pared with  the  advantage  of  almost  wholly  excluding  the  tinted 
fringe  which  had  so  long  vexed  astronomers.  In  the  eyeball  are 
first  a  crystalline  lens,  next  an  aqueous  humor,  third  a  vitreous 
humor;  these  three  so  vary  in  their  qualities  of  refraction  and 
dispersion  as  to  render  images  quite  free  from  color  fringes. 
Compound  lenses  on  the  Dollond  principle,  repeating  the  struc- 


B 


A  is  flint  glass, 
B  is  crown  glass. 
They  unite  to 
form  an  achro- 

,   matic  lens. 


B,  C,  F,  prism  crown  glass. 
C,  D,  F,  prism  flint  glass, 
more  dispersive  than  crown 
glass.  The  beam  S  emerges 
as  E,  but  little  decomposed. 
Were  A,  B,  F  a  prism  of 
one  kind  of  glass,  E  would  be 
much  decomposed. 


ture  of  an  eyeball,  are  used  in  all  good  telescopes,  microscopes, 
and  cameras,  and  are  now  executed  in  varieties  of  Jena  glass 
which  bring  perturbing  hues  to  the  vanishing  point.  In  their 
achromatic,  or  color-free,  lenses  and  their  cameras,  or  dark  cham- 
bers, our  photographic  instruments  much  resemble  the  eye.  In- 
deed, it  may  be  that  when  we  see  an  object  the  impression  is  due 
to  a  succession  of  fleeting  photographs,  following  each  other  so 
rapidly  on  the  retina  as  to  seem  a  permanent  picture.  The  eye, 
furthermore,  is  stereoscopic;  by  uniting  two  images  seen  from 
slightly  differing  points  of  view,  it  enables  us  to  judge  of  size, 
solidity,  and  distance. 


256 


NATURE  AS  TEACHER 


A 


Lever  of  the  Is.' f Order. 


Long  before  there  was  a  philosopher  to  classify  levers   into 
distinct  kinds,  the  foot  of  man  was  affording  examples  of  levers 
of  the  first  and  second  orders,  and  his  fore- 
Limbs  and  Lungs     arm  °f  a  lever  of  the  third  order.  Ages  before 
as  Prototypes.        the    crudest    bagpipe    was    put    together,    the 
lungs  by  which  they  were  to  be  blown,  and  the 
larynx  joined  to  those  lungs,  were  displaying  a  wind  instrument 
of  perfect  model.     The  wrists,  ankles,  and  vertebrae  of  Hooke 
B  might  well  have  served  him  in  de- 

signing his  universal  joint.  Indeed 
weapons,  tools,  instruments,  ma- 
chines, and  engines  are,  after  all,  but 
extensions  and  modified  copies  of 
the  bodily  organs  of  the  inventor 
himself. 

Canals  have  called  forth  the  in- 
genuity of  an  army  of  engineers; 
ever  since  the  first  heart-throb,  the 
circulation  of  the  human  blood  was 
exemplifying  a  system  in  which  the 
canal  liquid  and  the  canal  boats  move 
together,  making  a  complete  circuit 
twice  in  a  minute,  distributing  sup- 
plies wherever  required,  and  taking 
up  without  stopping  return  loads 
wherever  they  are  found  ready.  The 
heart,  with  its  arteries  and  veins, 
forms  a  distributing  apparatus  which 
carries  heat  from  places  at  which  it 
is  generated,  or  in  excess,  to  places 

where  it  is  deficient,  tending  to  establish  a  uniform,  healthful  tem- 
perature. To  copy  all  this,  with  the  ven- 
tilating appliances  prefigured  in  the 
lungs,  is  a  task  which  in  our  huge 
modern  buildings  demands  the  utmost 
skill  of  the  architect  and  engineer. 

In  a  great  city  each  branch  post  office 
is  connected  solely  with  headquarters,  to  Arm  holding  ball. 


Lever  of  1he  2n.<l  Order. 


Lever  of  the  3^ Order. 

P,  power.     F,  fulcrum. 
W,  weight. 


CENTRAL  STATIONS  257 

which  it  sends  its  letters,  papers,  and  parcels,  receiving  in  return 
its  batches  for  local  distribution.  For  each  branch  office  to  com- 
municate with  every  other  would  be  so  costly 

,  .        .  Postal  and  Tele- 

and  cumbrous  a  plan  as  to  be  quite  imprac-       phonic  service. 

ticable.  Our  postal  method  is  adopted  in 
every  telephonic  service ;  Z  communicating  with  D  or  M  only 
after  he  has  had  his  line  joined  to  the  central  switchboard  which 
connects  with  every  telephone  in  the  whole  system.  All  this  was 
prophesied  in  the  remote  ancestry  of  both  postmasters  and  elec- 
tricians as  their  nerves  took  the  paths  of  what  is  in  effect  a  com- 
plete telegraphic  circuit,  with  separate  up  and  down  lines  and  a 
central  exchange  in  the  brain,— that  prototype  of  all  other  means 
of  co-ordination. 

Pianos,  organs,  and  other  musical  instruments  yield  their  notes 
by  the  vibration  of  strings,  pipes,  or  reeds  of  definite  size  and 
form.     Across  the  larynx,  the  box-like  organ 
of  the  throat,  the  vocal   cords  vibrate   in   an        Fibrils  of  the 
identical  way.     When  we  sing  a  note  into  an        Ear  and  Eye. 
open  piano,  the  string  capable  of  giving  out 
that  note  at  once  responds.    Helmholtz  believed  that  in  the  ear  the 
delicate,  graduated  structures,  known  as  the  rods  of  Corti,  vibrate 
in  the  same  way  when  sound-waves  reach  them,  giving  rise  to 
auditory  impressions.     Analogous  in  operation  are  the  fibrils  of 
the  eye  which  respond  to  light-waves  of  various  length  and  in- 
tensities.    The  human  eye  has  muscles  which  modify  its  globu- 
larity,  rendering  its  lenses  more  or  less  convex.     A  cav  has  a 
higher  degree  of  this  kind  of  ability,  so  that  it  can  dilate  its  pupil 
so  much  as  to  see  clearly  in  a  feeble  light.    A  man  who  remains  in 
a  darkened  room  so  rests  his  nerves  of  vision  that  in  four  or  five 
hours  he  can  readily  discern  what  would  be  unseen  were  he  newly 
brought  into  the  darkness. 

Not  only  in  the  frame  of  man,  but  in  the  bodies  of  the  lower 
animals,  are  suggestions  which  ingenuity  might  well  have  acted 
upon  in  the  past,  or  worthily  pursue  in  the 
future.     The  science  of   electricity  was   born   The  Electric  Eel. 
only  with  the  nineteenth  century  because  the 
gymnotus,  or  electric  eel,  had  not  been  understandingly  dissected. 
Its  tissues  disclose  the  very  arrangement  adopted  by  Volta  in  his 


258 


NATURE  AS  TEACHER 


A  Beaver  Tooth 
Sharping 


first  crude  battery,  namely,  layers  of  susceptible  material  sur- 
rounded by  slightly  acid  moisture.  The  characteristics  of  this  eel 
have  their  homologies  in  the  human  body;  in  the  muscles  which 
bend  the  fore-arm,  for  example,  are  nearly  a  million  delicate 
fibrils  comparable  in  structure  with  the  columnar  organs  of  the 
gymnotus.  These  fibrils  are  so  easily  excited  by  electricity  as  to 
denote  an  essential  similarity  of  build.  Both  the  columnar  layers 
of  the  eel  and  the  fibrils  of  human  muscle  are  affected  in  the  same 
way  by  strychnine  and  by  an  allied  substance,  curare. 

The  frames  of  other  animals  furnish  forth  a  goodly  round  of 
analogies    with    recent    products    of    mechanical    ingenuity.      A 
beaver  tooth  might  well  have  been  the  model 
for  a  self-sharpening  plowshare,  widely  used 

throughout  the  world-      This  tooth  has  a  thin 
outer    layer    of    hard    enamel,    within    which, 

dentine,  less  hard,  makes  up  the  rest  of  the  structure.  Gnawing 
wears  the  dentine  much  more  than  the  enamel,  so  that  the  tooth 

takes  on  a  bevel  resembling  that  of  the 
chisel  which  pays  frequent  visits  to  a 
carpenter's  oil-stone.  The  scale  of 
enamel  gives  keenness,  the  dentine  en- 
sures strength,  so  that  the  tooth 
sharpens  itself  by  use,  instead  of 
growing  dull.  Much  the  same  struc- 
ture  is  repeated  in  a  plowshare  by 
chilling  the  underskin  of  the  steel  to 

extreme  hardness,  while  the  upper  face  of  the  share  is  left  com- 
paratively soft.  As  it  goes  through  the  ground  the  upper  face 
wears  away  so  as  to  yield  a  constantly  sharpened  edge  of  the  thin 
chilled  under  metal.  Thus  the  heavy  draft  of  a  dull  share  is 
avoided  without  constant  recourse  to  the  blacksmith  for  re- 
sharpening. 

In  another  field  of  ingenuity  a  great  inventor  scored  a  success, 

simply  by  deliberately  taking  a  lesson  from  nature.    James  Watt, 

to  whom  the  modern  steam  engine  is  most  in- 

Shaping  a  Tube,      debted  for  its  excellence,  was  once  consulted  by 

the  proprietors  of  the  Glasgow  Water  Works, 

as  to  a  difficulty  that  had  occurred  in  laying  pipes  across  the  river 


Beaver  teeth. 


LESSONS  FROM  ANIMALS 


259 


Clyde  to  the  Company's  engines :  the  bed  of  the  river  was  covered 

with  mud  and  shifting  sand,  was  full  of  inequalities,  and  subject 

to  a  current  at  times  of  considerable  force.  With  the  structure  of 

a  lobster's  tail  in  his  mind, 

Watt   drew   a   plan    for   an 

articulated    suction-pipe,    so 

jointed   as   to  accommodate 

itself  to  the  shifting  curves 

of     the     river-bed.        This 

crustacean  tube,  two  feet  in 

diameter,  and  one  thousand 

feet    in    length,     succeeded 

perfectly    in    its    operation. 

To-day    powerful    hydraulic 

dredges    discharge    through 

piping    with    flexible    joints 

such    as    Watt    devised;    in 

one  instance  this  piping  is 

5700  feet  in  length. 

In  many  another  case  art 
has  used  a  gift  of  nature 
simply  as  received,  and  then 
improved  upon  it.  In  mak- 


Narwhal  with  a  twisted  tusk. 
Reproduced  from  the  Scientific 
American,  New  York,  by  permis- 
sion. 


ing  their  harpoons  the  Es- 
kimo used  the  spiral  teeth 

of  the  narwhal ;  rinding  their  shape  advantageous,  they  copied  it 
for  arrowheads.  This  is  undoubtedly  one  of  the  origins  of  the 
screw  form,  of  inestimable  value  to  the  mechanic  and  engineer. 
Savages  turn  birds  and  beasts  to  account  as  food,  clothing,  and 
materials  for  weapons  and  tools ;  they  also  observe  with  profit  the 
instincts  of  these  creatures.  Le  Vaillant,  the 
famous  explorer,  tells  us  that  in  Africa  the 
negroes  eat  any  strange  food  they  see  the  mon- 
keys devour,  well  assured  that  it  will  prove 
wholesome.  When  the  surveyors  of  the  first  transcontinental 
railroad  of  America  began  their  labors,  they  gave  diligent  heed 
to  the  trails  of  buffaloes  in  the  Rocky  Mountains,  believing  that 
these  sagacious  brutes  in  centuries  of  quest  had  discovered  the 


Lessons  from 

Lower  Animals : 

A  Tool-Using 

Wasp. 


260 


NATURE  AS  TEACHER 


easiest  passes.  In  constructive  powers  bees,  ants  ana  wasps  far 
outrank  quadrupeds.  Indeed  one  of  the  supreme  feats  of  human 
architecture,  the  dome,  forms  part  of  the  nest  of  the  warrior  white 
ant,  Termes  bellicosus. 


Lower  part  of  warrior  ants'  nest,  showing  dome. 

It  is  deemed  a  mark  of  unusual  intelligence  when  an  ape,  of 
kin  to  man  himself,  uses  a  stone  as  a  hammer  wherewith  to  break 

open  a  nut,  and  yet  the  like  in- 
telligence is  displayed  by  Am- 
morphila  urnaria,  as  described 
by  Dr.  and  Mrs.  George  W. 
Peckham  in  their  charming 
book,  "Wasps  Solitary  and 
Social"  i1 

"Just  here  must  be  told  the 
story  of  one  little  wasp  whose 
individuality  stands  out  in  our 


minds  more  distinctly  than 
that  of  any  of  the  others.  We 
remember  her  as  the  most 
fastidious  and  perfect  little 
worker  of  the  whole  season, 
so  nice  was  she  in  her  adaptation  of  means  to  ends,  so  busy  and 
contented  in  her  labor  of  love,  and  so  pretty  in  her  pride  over  the 
completed  work.  In  filling  up  her  nest  she  put  her  head  down 


Wasp  using  a  pebble  as  a  hammer. 
From  "Wasps  Solitary  and  Social," 
Copyright,  1905,  by  George  W.  Peck- 
ham  and  Elizabeth  G.  Peckham.  Re- 
produced by  their  permission. 


1  Published  by  Houghton   Mifflin  &  Co.,  Boston. 


OXYGEN  FROM  AIR  261 

into  it  and  bit  away  the  loose  earth  from  the  sides,  letting  it  fall 
to  the  bottom  of  her  burrow,  and  then,  after  a  quantity  had  ac- 
cumulated, jammed  it  down  with  her  head.  Earth  was  then 
brought  from  the  outside  and  pressed  in,  and  then  more  was  bit- 
ten from  the  sides.  When  at  last  the  filling  was  level  with  the 
ground,  she  brought  a  quantity  of  fine  grains  of  dirt  to  the  spot, 
and  picking  up  a  small  pebble  in  her  mandibles,  used  it  as  a 
hammer  in  pounding  them  down  with  rapid  strokes,  thus  making 
this  spot  as  hard  and  firm  as  the  surrounding  surface." 

It  was  a  wasp,  too,  which  suggested  to  Reaumur,  as  he  exam- 
ined its  nest,  that  wood  might  well  serve  as  the  raw  material  for 
paper,  and  serve  it  does  to  the  amount  of  millions  of  tons  a  year. 
To-day  we  have  as  a  new  fabric  for  garments,  glanz-stoff,  an 
artificial  silk  produced  from  cellulose;  its  German  manufacturers 
have  imitated  as  nearly  as  they  could  the  silk-worm's  thread,  just 
as  for  some  years  the  filaments  for  incandescent  lamps  have  been 
made  from  liquid  cellulose  forced  through  minute  holes.  At  first 
bamboo  fibres  were  used  for  this  purpose;  to-day  art  furnishes 
a  thread  of  more  uniform  and  lasting  quality.  This  achievement 
is  of  a  piece  with  many  another.  To-day  when  an  inventor  seeks 
to  imitate  a  natural  product  he  does  so  with  a  power  of  analysis, 
a  wealth  of  new  materials,  such  as  his  forerunners  could  not  have 
imagined.  It  is  in  laboratories  stocked  more  diversely  than  ever 
before,  with  their  resources  better  understood  than  at  any  earlier 
time,  that  the  triumphs  of  modern  ingenuity  proceed. 

In  all  likelihood  one  of  the  feats  of  nature  soon  to  be  paralleled 
by  art,  in  an  economical  way,  will  be  one  phase  of  the  breathing 
process;  every  time  we  inflate  our  lungs  their 
tissues   perform   a    feat   which   has   thus    far      The  Separating 
baffled  imitation  except  in  a  roundabout  and  ^*Un  gl 

wasteful  manner.  Air  is  a  mixture  of  oxygen 
and  nitrogen ;  the  work  of  life  is  subserved  by  the  oxygen  only, 
which  is  separated  from  air  by  the  lungs  and  passed  into  the 
current  of  the  blood.  Oxygen  and  nitrogen,  like  any  other  two 
gases,  tend  forcibly  to  diffuse  into  each  other,  as  we  may  see  in 
the  distension  of  a  thin  rubber  sheet  dividing  a  container  into 
two  parts,  one  filled  with  oxygen,  the  other  with  nitrogen.  To 
overcome  the  force  of  diffusion  which  keeps  together  the  oxygen 


262  NATURE  AS  TEACHER 

and  nitrogen  forming  a  cubic  foot  of  air,  of  ordinary  tempera- 
ture, would  require  such  an  effort  as  would  lift  twenty-one  pounds 
one  foot  from  the  ground.  This  task  the  lungs  accomplish  by 
means  which  elude  observation  or  analysis.  It  would  mean  much 
to  the  arts  if  this  parting  power  could  be  imitated  simply  and 
cheaply.  In  common  combustion  each  volume  of  oxygen  which 
unites  with  the  fuel,  carries  with  it  four  volumes  of  nitrogen 
which  have  to  be  heated,  not  only  reducing  the  temperature  of  the 
flame,  but  removing  in  sheer  waste  much  of  the  heat.  A  supply 
of  oxygen  free  from  admixture  would  double  the  value  of  fuel 
for  many  purposes,  creating  a  temperature  so  high  that  it  would 
be  difficult -to  find  building  materials  refractory  enough  for  the 
furnaces.  Cheap  oxygen  would  greatly  increase  the  light  de- 
rivable from  oil  and  gas,  as  proved  in  the  brilliancy  of  an  oxy- 
hydrogen  jet.  In  bleaching  and  in  scores  of  other  processes, 
oxygen  is  so  valuable  that,  notwithstanding  its  present  cost,  the 
demand  for  it  steadily  increases.  Cannot  the  lungs,  chemically  or 
mechanically,  be  copied  so  as  to  yield  this  gas  at  a  low  price  for  a 
thousand  new  services? 

In  addition  to  separating  oxygen  from  air  our  vital  organs  are 
every  moment  performing  chemical  tasks  just  as  elusive.  The 
liver,  for  instance,  is  a  sugar-maker.  The  elaboration  of  living 
tissue  is  of  transcendent  interest  to  the  physiologist ;  it  is  fraught 
with  the  same  attraction  to  the  chemist  who  would  build  com- 
pounds from  their  elements,  to  the  engineer  who  would  transform 
heat  or  chemical  energy  into  motive  power  with  less  than  the 
enormous  loss  of  our  present  methods. 

In  1887  the  late  Professor  S.  P.  Langley  of  Washington  began 
experiments  in  mechanical  flight.  He  found  that  one  horse- 
power will  support  in  calm  air  and  propel  at 
Flight.  forty-five  miles  an  hour  a  wing-plane  weighing 

209  pounds.  Dr.  A.  F.  Zahm,  of  the  Catholic 
University  of  America,  at  Washington,  has  recently  ascertained 
that  a  thin  foot-square  gliding  plane  weighing  one  pound  soars 
with  the  least  expenditure  of  power  at  about  40  miles  an  hour, 
while  at  80  miles  the  power  required  is  more  than  twice  as  much. 
As  engines  have  been  made  weighing  less  than  ten  pounds  per 
horse-power,  capable  of  yielding  a  horse-power  for  five  hours 


LIGHT  WITHOUT  HEAT  268 

with  four  pounds  of  oil,  we  are  plainly  approaching  the  mastery 
of  the  air,— so  freely  exercised  by  the  sparrow  and  the  midge. 
Among  the  students  eager  in  this  advance  are  the  men  who 
examine  with  the  camera  how  wings  of  diverse  types  behave  in 
flight,  and  then  endeavor  to  imitate  the  strongest  and  swiftest  of 
these  wings. 

Professor  Langley  conducted  another  inquiry  of  fascinating 
interest,  this  time  respecting  those  natural  light-producers,  the 
fireflies,    especially    the     large    and    brilliant 
species  indigenous  to  Cuba,  Pyrophorns  nocti-  Light. 

Incus.    As  the  result  of  refined  measurements 
with  the  spectroscope  and  the  bolometer,  the  most  delicate  heat 
detector  known  to  the  laboratory,  he  said :  "The  insect  spectrum 
is     lacking     in     rays     of     red 
luminosity    and    presumably    in 
the    infra-red    rays,    usually    of 
relatively  great  heat,  so  that  it 
seems  probable  that  we  have  here 
light  without  heat."     When  we 
remember  that  ordinary  artificial 

light  is  usually  accompanied  by  Cub'an  firefly>  ,ife  size 

fifty  to  a  hundred  times  as  much 
energy  in  the  form  of  wasteful  and  injurious  heat,  we  see  the 
importance  of  this  research.  If  light  can  be  produced  without 
heat  by  nature,  why  not  also  by  art? 

Another  notable  case  of  efficiency  in  nature  has  already  been 
remarked,  namely,  the  conversion  by  the  animal  frame  of  fuel- 
values   into   mechanical   work.     This   is  of  a 
Converting  Heat     piece  with  the  chief  task  of  the  engineer  as  he 

Into  Work.  puts  his  engines  in  motion  by  burning  coal  or 
wood,  oil  or  gas.  It  is  a  remarkably  good 
steam  engine  which  yields  as  much  as  one  tenth  as  a  working  div- 
idend. Gas  engines  have  sprung  into  wide  popularity  because 
they  yield  larger  results,  in  extremely  favorable  cases  reaching 
thirty  per  cent.  A  heat  engine,  of  any  type,' has  its  effectiveness 
measured  by  comparing  in  absolute  units  the  heat  which  enters  it 
with  the  heat  which  remains  after  its  work  is  done.  The  zero  of 
the  absolute  scale  is  460°  below  the  zero  of  Fahrenheit.  So 


264  NATURE  AS  TEACHER 

that  if  an  engine  begins  work  at  920°  Fahr.  (1380°  absolute),  and 
the  working  substance  is  lowered  in  temperature  by  its  action  in 
the  machine  until  it  falls  to  460°  Fahrenheit  (920°  absolute),  the 
engine  has  a  gross  efficiency  of  one  third.  Economy  depends 
upon  employing  a  working  substance  at  the  highest  feasible  tem- 
perature in  such  a  mode  that  it  leaves  the  engine  at  the  lowest 
temperature  possible.  Hence  we  see  engineers  devising  super- 
heaters for  their  steam,  and  producing  metal  surfaces  which 
either  need  no  lubrication  at  all,  or  employ  such  a  lubricant  as 
graphite,  which  bears  high  temperatures  without  injury. 

Now  let  us  glance  at  the  mechanism  of  our  own  frames,  which, 
according  to  Professor  W.  O.  Atwater,  converts  about  twenty  per 
cent,  of  the  energy  value  of  our  food  into  mechanical  work.  This 
is  a  remarkable  performance,  especially  when  we  remember  that 
in  health  the  bodily  warmth  does  not  rise  above  98°  Fahrenheit. 
What  explains  this  amazing  effectiveness  at  a  temperature  so  far 
below  that  of  either  a  steam  engine  or  a  gas  engine?  A  simple 
experiment  may  be  illuminating.  We  take  a  plate  of  zinc  and  a 
plate  of  copper ;  although  they  seem  to  be  at  rest  we  know  them 
to  be  in  active  molecular  motion,  which  motion  is  set  free  when 
they  combine  with  oxygen  or  other  elements.  This  combination 
may  take  place  in  two  quite  different  ways,  which  we  will  now 
compare.  In  a  glass  jar,  nearly  rilled  with  a  solution  of  sulphuric 
acid  and  water,  we  immerse  the  plates  of  zinc  and  copper  without 
their  touching  each  other;  both  rise  in  temperature  as  they  cor- 
rode, as  they  unite  with  oxygen  from  the  surrounding  liquid.  We 
may,  if  we  wish,  employ  this  heat  in  driving  an  air  engine ;  but 
we  can  do  better  than  that,  for  an  air  engine  wastes  most  of  the 
heat  supplied  to  it.  We  stop  the  heating  process  by  joining  the 
two  plates  with  a  wire  through  which  now  passes  an  electric  cur- 
rent, our  simple  apparatus  now  forming  a  common  voltaic  cell. 
This  current  we  apply  to  lift  weights,  propel  a  fan,  or  execute 
any  other  task  we  please,  all  with  scarcely  any  waste  of  energy 
whatever.  The  instructive  point  is  that  now  chemical  union  is 
taking  place  without  heat,  in  a  mode  vastly  more  economical  and 
easy  to  manage  than  if  we  allowed  heat  to  be  generated,  and  then 
applied  it  in  an  engine  to  perform  work.  The  conclusion  is  ir- 
resistible :  in  the  animal  frame  the  conversion  of  molecular  energy 


FORESIGHT  BEGINS  265 

into  muscular  motion  is  by  electrical  means  and  no  other.  When 
the  engineer  learns  in  detail  how  the  task  is  executed,  and  imi- 
tates it  with  success,  he  will  escape  the  tax  now  imposed  on  every 
engine  which  sets  its  fuel  on  fire  as  the  first  step  in  converting 
latent  into  actual  motion. 

While  inventors  in  the  past  might  have  taken  many  a  hint  from 
nature,  as  a  matter  of  fact  they  seldom  did  so,  but  went  ahead, 
hit-or-miss,  failing  to  observe  that  what  they 

reached  with  much  laborious   fumbling,  often   Foresight  Instead 

f       ,  of  Hindsight, 

they  might  have  copied  directly  from  nature. 

In  Colorado  and  California  we  admire  the  dams  which  are  convex 
upstream,  withstanding  in  all  the  strength  of  an  arch  a  tremen- 
dous pressure :  this  very  plan  is  adopted  by  beavers  when  they 
build  in  a  swift  current,  as  one  may  see  in  many  streams  of  the 
Adirondacks.  In  the  rearing  of  irrigation  dams,  in  tasks  much 
more  difficult,  human  progress  has  gone  forward  by  empirical 
attempts  one  after  another,  and  science  has  followed,  long  after- 
ward, to  give  reasons  for  any  success  arrived  at  by  rule-of- 
thumb.  But  this  blundering  hindsight  is  being  replaced  by  a 
foresight  which  first  spies  out  what  may  be  hit,  and  then  never 
wastes  an  arrow.  Professor  R.  H.  Thurston  has  said :— "Bleach- 
ing and  dyeing  flourished  before  chemistry  had  a  name;  the  in- 
ventor of  gunpowder  lived  before  Lavoisier;  the  mariner's  com- 
pass pointed  the  seaman  to  the  pole  before  magnetism  took  form 
as  a  science.  The  steam  engine  was  invented  and  set  at  work, 
substantially  as  we  know  it  to-day,  before  the  science  of  thermo-x 
dynamics  was  dreamt  of;  the  telegraph  and  the  telephone,  the 
electric  light  and  the  railroad  have  made  us  familiar  with  marvels 
greater  than  those  of  fiction,  and  yet  they  have  been  principally 
developed,  in  every  instance,  by  men  who  had  acquired  less  of 
scientific  knowledge  than  we  demand  to-day  of  every  college-bred 
lad." 

To-day  the  leaders  in  applied  science  are  of  quite  other  stamp. 
They  keenlv  observe  what  nature  does,  either  in  spontaneous 
chemical  activities  or  in  the  functions  of  a  plant  or  an  animal, 
then  analyzing  the  process  with  more  and  more  insight  and  ac- 
curacy, they  ask,  How  may  this  with  economy  and  profit  be 
imitated  by  art?  A  feat  of  Professor  Henri  Moissan  is  typical 


266  NATURE  AS  TEACHER 

in  this  regard.  In  studying  diamonds  he  became  convinced  that 
they  have  been  produced  in  nature  from  ordinary  carbon  sub- 
jected to  extreme  temperatures  and  pressures.  Imitating  these 
heats  and  pressures  as  well  as  he  could,  he  manufactured  dia- 
monds from  common  graphite  in  an  electrical  furnace.  These 
gems  are  small,  but  they  gleam  with  promise  of  what  the  fully 
armed  physicist  and  chemist  may  achieve  in  duplicating  the  gifts 
of  nature  in  the  light  of  new  knowledge,  by  dint  of  new  resources. 


CHAPTER  XIX 

ORIGINAL  RESEARCH 

Knowledge  as  sought  by  disinterested  inquirers  ...  A  plenteous  harvest 
with  but  few  reapers  .  .  .  Germany  leads  in  original  research  .  .  .  The 
Carnegie  Institution  at  Washington. 

WE  have  now  taken  a  rapid  survey  of  invention  and  discovery 
in  the  fields  of  Form,  Size,  Properties,  Measurement,  and 
the  Teachings  of  Nature.  We  will  here  somewhat  change  our 
point  of  view  and  bestow  a  glance  at  the  characteristics  of  in- 
ventors and  discoverers,  noting  .their  powers  of  observation  and 
experiment,  their  patience  from  first  to  last  in  learning  from  other 
thinkers  and  workers  past  and  present.  What  any  one  man,  how- 
ever able,  can  discover  or  invent,  is  the  merest  trifle  in  com- 
parison with  the  resources  accumulated  since  the  dawn  of  human 
vvit.  And  yet  in  adding  a  little  to  what  he  has  learned,  that  little 
welds  and  vivifies  his  education  as  nothing  else  can.  In  setting 
out  to  add  to  known  truth  there  must  be  a  goodly  equipment  in 
knowledge  and  skill.  Knowledge,  therefore,  may  serve  as  a  start- 
ing point  for  the  survey  before  us. 

Success  in  discovery  and  invention,  as  m  the  case  of  a  Newton 
or  a  Watt,  depends  not  only  upon  rare  natural  faculty,  but  upon 
knowledge.     Dr.    Pye-Smith,    of   London,   an 
eminent  physician,  says  :— "Some  would  have         Knowledge 
us  believe  that  erudition  is  a  clog  upon  genius. 
This  question  has  often  been  discussed,  and  it  has  even  been 
maintained  that  he  is  most  likely  to  search  out  the  secrets  of  na- 
ture who  comes  fresh  to  the  task  with  faculties  unexhausted  by 
prolonged  reading,  and  his  judgment  uninfluenced  by  the  dis- 
coveries of  others.    This,  however,  is  surely  a  delusion.    Harvey 


268  ORIGINAL  RESEARCH 

could  not  have  discovered  the  circulation  of  the  blood  had  he  not 
been  taught  all  that  had  been  previously  learned  of  anatomy. 
True,  no  progress  can  be  made  by  the  mere  assimilation  of 
previous  knowledge.  There  must  be  an  intelligent  curiosity,  an 
observant  eye,  and  intellectual  insight.  Few  things  are  more  de- 
plorable than  to  see  talent  and  industry  employed  in  fruitless 
researches,  partly  rediscovering  what  is  already  fully  known,  or 
stubbornly  toiling  along  a  road  which  has  long  ago  been  found 
to  lead  no  whither.  We  must  then  instruct  our  students  to  the 
utmost  of  our  power.  Whether  they  will  add  to  knowledge  we 
cannot  tell,  but  at  least  they  shall  not  hinder  its  growth  by  their 
ignorance.  The  strong  intellect  will  absorb  and  digest  all  that 
we  put  before  it,  and  will  be  all  the  better  fitted  for  independent 
research.  The  less  powerful  will  at  least  be  kept  from  false  dis- 
coveries and  will  form,  what  genius  itself  requires,  a  competent 
and  appreciative  audience." 

American  inventors  echo  the  dictum  of  the  English  physician. 
Says  Mr.  Octave  Chanute : — "It  has  taken  many  men  to  bring  any 
great  invention  to  perfection,  the  last  successful  man  adding  little 
to  what  was  previously  known.  As  a  rule  the  basis  of  his  success 
lies  in  a  thorough  acquaintance  with  what  has  been  done  before 
him,  and  his  setting  about  his  work  in  a  thoroughly  scientific  way." 
Professor  W.  A.  Anthony  observes : — "If  the  army  of  would-be 
inventors  would  enter  the  field  with  a  full  knowledge  of  what 
science  has  already  done,  the  conquest  of  new  territory  would  be 
rapidly  accomplished."  To  the  same  effect  speaks  Mr.  Leicester 
Allen :— "While  rarely  there  appears  a  man  so  highlv  endowed  by 
nature  with  originating  faculty  that  we  call  his  talent  genius,  it 
will  be  found  in  the  last  analysis  that  his  inventive  power  lies, 
not  in  some  vague,  mysterious  intuition,  but  in  a  logical  mind  that 
can  draw  correct  inferences  from  established  premises ;  in  an 
analytical  mind  that  enables  him  to  reason  from  correct  data,  dis- 
covering those  which  are  false;  in  natural  and  cultivated  per- 
ceptive faculties  that  enable  him  to  determine  the  effect  of  a  given 
set  of  conditions,  and  through  exercise  of  which  he  is  able  to  place 
clearly  before  his  mental  vision  the  exact  statement  or  proposition 
which  defines  the  thing  to  be  accomplished ;  in  the  ability  to  con- 
centrate his  attention  upon  the  problem  in  hand  to  the  exclusion 


SCOPE  FOR  DISCOVERY  269 

of  everything  else,  for  the  time  being,  and  a  perseverance  that  will 
not  be  denied — that  failure  cannot  wear  out." 

'To  many,"  says  Sir  Michael  Foster,  Professor  of  Physiology 
at  Cambridge,  "scientific  knowledge  seems  to  be  advancing  by 
leaps  and  bounds;  every  day  brings  its  fresh 
discovery,  opening  up  strange  views,  turning  Much  is  Still  to 
old  ideas  upside  down.  Yet  every  thoughtful  be  Discovered. 
man  of  science  who  has  looked  round  on  what 
others  beside  himself  are  doing  will  tell  you  that  nothing  weighs 
more  heavily  on  his  mind  than  this :  the  multitude  of  questions 
crying  aloud  to  be  answered,  the  fewness  of  those  who  have  at 
once  the  ability,  the  means,  and  the  opportunity  of  attempting  to 
find  the  answers.  Among  the  many  wants  of  a  needy  age,  few,  if 
any,  seem  to  him  more  pressing  than  that  of  the  adequate  en- 
couragement and  support  of  scientific  research."  With  his  own 
field  of  science  in  view  he  continues:  "We  want  to  know  more 
about  the  causation  and  spread  of  disease  and  about  the  circum- 
stances affecting  health  before  we  can  legislate  with  certainty  of 
success.  At  home  we  want  to  know  more  about  the  spread  of 
tubercle,  of  typhoid  fever,  and  other  infectious  diseases ;  we  want 
to  know  more  about  the  proper  means  to  secure  that  the  water  we 
drink,  the  food  we  eat,  and  the  air  we  breathe,  should  not  be 
channels  of  disease;  we  want  to  know  more  about  the  invisible 
elfic  micro-organisms  which  swarm  around  us,  to  learn  which  are 
our  friends,  and  which  our  foes,  how  to  nourish  the  one,  how  to 
defeat  the  other ;  we  want  to  know  the  best  way  to  shield  man  in 
the  factory  and  the  workshop  against  the  works  of  man." 

As  to  the  fewness  of  those  who  have  the  highest  capacity  for 
original  research,  who  have  it  in  them  to  add  to  known  truth  in  a 
notable  way,  Professor  Simon  Newcomb  of  Washington,  the 
acknowledged  dean  of  science  in  America,  has  said: — "It  is  im- 
pressive to  think  how  few  men  we  should  have  to  remove  from 
the  earth  during  the  past  three  centuries  to  have  stopped  the  ad- 
vance of  our  civilization.  In  the  seventeenth  century  there  would 
only  have  been  Galileo,  Newton  and  a  few  other  contemporaries ; 
in  the  eighteenth,  they -could  almost  have  been  counted  on  the 
fingers ;  and  they  have  not  crowded  the  nineteenth.  Even  to-day, 
almost  every  great  institution  for  scientific  research  owes  its  being 


270  ORIGINAL  RESEARCH 

to  some  one  man,  who,  as  its  founder  or  regenerator,  breathed  into 
it  the  breath  of  life.  If  we  think  of  the  human  personality  as 
comprehending  not  merely  mind  and  body,  but  all  that  the  brain 
has  set  in  motion,  then  may  the  Greenwich  Observatory  of  to-day 
be  called  Airy;  that  of  Pulkowa,  Struve;  the  German  Reichsan- 
stalt,  Helmholtz;  the  Smithsonian  Institution,  Henry;  the  Har- 
vard Museum  of  Comparative  Zoology,  Agassiz;  the  Harvard 
Observatory,  Pickering." 

The  late  Professor  Robert  H.  Thurston,  of  Cornell  University, 

once  said :— "Methods  of  planning  scientific  investigation  involve, 

first,  the  precise  definition  of  the  problem  to  be 

Planning  an  solved ;  secondly,  they  include  the  ascertain- 
ment of  'the  state  of  the  art/  as  the  engineer 
would  say,  the  revision  of  earlier  work  in  the  same  and  related 
fields,  and  the  endeavor  to  bring  all  available  knowledge  into  re- 
lation with  the  particular  case  in  hand ;  then  the  investigator  seeks 
information  which  will  permit  him,  if  possible,  to  frame  some 
theory  or  hypothesis  regarding  the  system  into  which  he  proposes 
to  carry  his  experiment,  his  studies,  and  his  logical  work,  such  as 
will  serve  him  as  a  guide  in  directing  his  work  most  effectively. 

"The  empirical,  the  imaginative,  and  even  the  guess  work  sys- 
tems, or  perhaps  lack  of  system,  have  their  place  in  scientific  re- 
search. The  dim  Titanic  figure  of  Copernicus  seems  to  rear  itself 
out  of  the  dull  flats  around  it,  pierces  with  its  head  the  mists  that 
overshadow  them  and  catches  the  first  glimpse  of  the  rising  sun. 
But  first  Copernicus  made  a  shrewd  guess,  and  then  followed  with 
mathematical  work  and  confirmation.  .  .  .  Kepler,  also,  was 
strong  almost  beyond  competition  in  speculative  subtlety  and 
innate  mathematical  perception.  .  .  .  For  nineteen  years  he 
guessed  at  the  solution  of  a  well-defined  problem,  finding  his 
speculation  wrong  every  time,  until  at  last  a  final  trial  of  a  last 
hypothesis  gave  rise  to  deductions  confirmed  by  observation.  His 
first  guess  was  that  the  orbits  of  the  planets  were  circular,  next 
that  they  were  oval,  and  last  that  they  were  elliptical." 

Pascal,  great  in  what  he  knew,  was  great  also  in  what  he  was. 
Walter  Pater  thus  depicts  his  powers :— "Hidden  under  the  ap- 
parent exactions  of  his  favorite  studies,  imagination,  even  in  them, 


THE  INVENTOR'S  PREPARATION   271 

played  a  large  part.  Physics,  mathematics,  were  with  him  largely 
matters  of  intuition,  anticipation,  precocious  discovery,  short  cuts, 
superb  guessing.  It  was  the  inventive  element  in  his  work,  and 
his  way  of  painting  things  that  surprised  those  most  able  to  judge. 
He  might  have  discovered  the  mathematical  sciences  for  himself, 
it  is  alleged,  had  his  father,  as  he  once  had  a  mind  to  do,  withheld 
him  from  instruction  in  them." 

No  such  gift  of  intuition  as  that  displayed  by  Pascal  fell  to 
the  lot  of  Buffon,  who  tells  us :— "Invention  depends  on  patience. 
Contemplate  your  subject  long.  It  will  gradually  unfold  itself, 
till  an  electric  spark  convulses  the  brain  for  a  moment." 

As  to  the  modes  in  which  invention  manifests  itself,  Mr.  Wil- 
liam H.  Smyth  says :— "Examine  at  random  any  one  of  half  a 
dozen  lines  of  mechanical  invention,  one  characteristic  common 
to  them  all  will  instantly  arrest  attention — they  present  nothing 
more  than  a  mere  outgrowth  of  the  manual  processes  and  ma- 
chines of  earlier  times.  Some  operation,  once  performed  by 
hand  tools,  is  expedited  by  a  device  which  enables  the  foot  as  well 
as  the  hand  to  be  employed.  Then  power  is  applied ;  the  hand  or 
foot  operation,  or  both,  are  made  automatic,  and  possibly,  as  a 
still  further  improvement,  several  of  these  automatic  devices  are 
combined  into  one.  All  the  while  the  fundamental  basis  is  the 
old,  original  hand  process ;  hence,  except  in  the  extremely  improb- 
able event  that  this  was  the  best  possible  method,  all  the  successive 
improvements  are  simply  in  the  direction,  not  of  real  novelty,  but 
of  mere  modification  and  multiplication.  The  most  important  and 
radical  departures  from  old  methods,  by  which  many  of  the  in- 
dustries of  the  world  have  been  completely  revolutionized,  are 
nearly  always  originated  by  persons  wholly  ignorant  of  the  ac- 
cepted practice  in  the  particular  industry  concerned.  The  first 
and  most  important  prerequisite  to  invention  is  an  absolutely 
clear  insight  into,  and  a  comprehensive  grasp  of,  all  the  condi- 
tions involved  in  the  problem.  A  scheme  for  the  cultivation  of 
invention  should  in  part  include:— (i)  Accurate  and  methodical 
observation.  (2)  Cultivation  of  memory  and  the  faculty  of  asso- 
ciation. (3)  Cultivation  of  clear  visualization.  (4)  Logical 
reasoning  from  actual  observation.  The  course  should  include 


272  ORIGINAL  RESEARCH 

exercises  in  drawing  from  simple  objects,  and  the  solution  of  a 
simple  problem,  such  as  that  of  a  can-soldering  machine." 

Investigators   are   never   so   useful   as   when   thoroughly    dis- 

interested ;  let  them  find  what  they  may,  it  will  either  have  worth 

in  itself  or  lead  to  something  which  has.     Dr. 

The  Debt  to         Pye-Smith  says  :— 

Research  in  «  "  ^         Q£ 


Medicine.  .  ,  .  , 

science    which    were    valueless    at    their    dis- 

covery, but  which,  little  by  little,  fell  into  line  and  led  to  appli- 
cations of  the  highest  importance—  the  observation  of  the  tarnish- 
ing of  silver,  the  twitching  of  the  frog's  leg,  were  the  origin  of 
photography  and  telegraphy  ;  the  abstract  problem  of  spontaneous 
generation  gave  rise  to  the  antiseptics  of  surgery.  ...  In 
medicine,  as  in  every  other  practical  art,  progress  depends  upon 
knowledge,  and  knowledge  must  be  pursued  for  its  own  sake 
without  continually  looking  about  for  its  practical  applications. 
Harvey's  great  discovery  of  the  circulation  of  the  blood  was  a 
strictly  physiological  discovery,  and  had  little  influence  upon  the 
healing  art  until  the  invention  of  auscultation.  So,  also,  Dubois 
Reymond's  investigation  of  the  electrical  properties  of  muscle 
and  nerve  was  purely  scientific,  but  we  use  the  results  thus  ob- 
tained every  day  in  the  diagnosis  of  disease,  in  its  successful 
treatment,  and  in  the  scarcely  less  important  demonstration  of 
the  falsehoods  by  which  the  name  of  electricity  is  used  for  pur- 
poses of  gain.  The  experiments  on  blood  pressure,  begun  by 
Hales,  and  carried  to  a  successful  issue  in  our  own  time  by  Lud- 
wig,  have  already  led  to  knowledge  which  we  use  every  day 
by  the  bedside,  and  which  only  needs  the  discovery  of  a  better 
method  of  measuring  blood  pressure  during  life  to  become  one  of 
our  foremost  and  most  practical  aids  in  treatment.  Again,  we 
can  most  of  us  remember  using  very  imperfect  physiological 
knowledge  to  fix,  more  or  less  successfully,  the  locality  of  an 
organic  lesion  of  the  brain.  I  also  remember  such  attempts  being 
described  as  a  mere  scientific  game,  which  could  only  be  won  after 
the  player  was  beaten,  since  when  the  accuracy  of  diagnosis  was 
established,  its  object  was  already  lost;  but  who  would  say  this 
now,  when  purely  physiological  research  and  purely  diagnostic 
success  have  led  to  one  of  the  most  brilliant  achievements  of 


RESEARCH  PRECEDES  INVENTION  273 

practical  medicine,  the  operative  treatment  of  organic  diseases  of 
the  brain  ?" 

The  prevention  of  disease,  as  important  as  its  cure,  owes  an 
incalculable  debt  to  Louis  Pasteur.  De  Varigny  says  in  "Ex- 
perimental Evolution"  :— 

"Pasteur,  about  1850,  spent  a  long  time  in  seemingly  very 
speculative  and  very  idle  studies  of  dissymmetry  and  symmetry 
in  various  crystals,  especially  those  of  tartaric  acid ;  the  practical 
value  of  such  investigations  seemed  to  be  naught,  and  at  all  events 
it  had  no  interest  save  for  the  elucidation  of  some  points  in  crys- 
tallography. But  this  investigation  led  logically  to  the  study  of 
fermentation,  and  the  final  outcome  of  Pasteur's  work  has  been 
—leaving  out  the  stepping  stones— the  discovery  of  the  real  cause 
of  a  large  number  of  diseases,  the  cure  of  one  of  them,  and  the 
expectation,  based  on  facts,  that  all  these  diseases  can  be  defeated 
by  appropriate  methods." 

What  is  true  in  medicine  is  equally  true  in  physics.  Concerning: 
the  debt  of  the  inventor  to  the  man  of  physical  research,  Mr. 
Addison  Browne  has  this  to  say  :— 

"A  few  weeks  ago  I  was  talking  with  an  Research  in 
electrician  who  has  made  several  very  interest-  Physics  and 
ing  and  important  inventions.  I  asked  hirn  of 
how  much  importance  he  conceived  that\the  scientific  men  of  the 
closet^  the  original  investigators,  so-called,  had  been  in  working 
out  the  great  inventions  of  electricity  during  the  last  fifty  years 
—telegraphs,  cables,  telephones,  electric  lighting,  electric  motors; 
and  whether  these  achievements  were  not  in  reality  due  mainly 
to  practical  men,  the  inventors  who  knew  what  they  were  after, 
rather  than  to  the  men  of  science  who  rarely  applied  their  work 
to  practical  use.  He  said,  The  scientific  men  are  of  the  utmost 
importance ;  everything  that  has  been  done  has  proceeded  upon 
the  basis  of  what  they  have  previously  discovered,  and  upon  the 
principles  and  laws  which  they  have  laid  down.  Nowadays  we 
never  work  at  random— I  go  to  my  laboratory,  study  the  applica- 
tion of  the  principles,  facts  and  laws  which  the  great  scientists 
like  Faraday,  Thomson  and  Maxwell  have  worked  out,  and  en- 
deavor to  find  such  devices  as  shall  secure  my  aim/  As  Tyndall 
said,  'Behind  all  our  practical  applications  there  is  a  region  of  in- 


274  ORIGINAL  RESEARCH 

tellectual  action  to  which  practical  men  have  rarely  contributed,  rjut 
from  which  they  draw  all  their  supplies.  Cut  them  off  from  that 
region  and  they  become  eventually  helpless.'  " 

Research  is  golden  only  when  brought  to  fruit  by  co-operation. 
To  quote  Professor  Tyndall : — 

"To  keep  science  in  healthy  play  three  classes  of  workers  are 
necessary:  (i)  The  investigators  of  natural  truth,  whose  voca- 
tion it  is  to  pursue  that  truth,  and  extent  the  field  of  discovery  for 
its  own  sake,  without  reference  to  practical  ends.  (2)  The 
teachers  who  diffuse  this  knowledge.  (3)  The  appliers  of  these 
principles  and  truths  to  make  them  available  to  the  needs,  the 
comforts,  or  the  luxuries,  of  life.  These  three  classes  ought  to  co- 
exist and  interact." 

Concerning  the  larger  problems  of  engineering  research,  Pro- 
fessor Osborne  Reynolds,  of  Owens  College,  Manchester,  says  :— 

"Every  one  who  has  paid  attention  to  the  history  of  mechanical 
progress  must  have  been  impressed  by  the  smallness  in  number 
of  recorded  attempts  to  decide  the  broader  questions  in  engineering 
by  systematic  experiments,  as  well  as  by  the  great  results  which, 
in  the  long  run,  have  apparently  followed  as  the  effect  of  these 
few  researches.  I  say  'apparently/  because  it  is  certain  that  there 
have  been  other  researches  which  probably,  on  account  of  failure 
to  attain  some  immediate  object,  have  not  been  recorded,  although 
they  may  have  yielded  valuable  experience  which,  though  not  put 
on  record,  has,  before  it  was  forgotten,  led  to  other  attempts.  But 
even  discounting  such  lost  researches  it  is  very  evident  that 
mechanical  science  was  in  the  past  very  much  hampered  by  the 
want  of  sufficient  inducement  to  the  undertaking  of  experiments 
to  settle  questions  of  the  utmost  importance  to  scientific  advance, 
but  which  have  not  promised  pecuniary  results,  scientific  questions 
which  involved  a  greater  sacrifice  of  time  and  money  than  the 
individuals  could  afford.  The  mechanical  engineers  recently  in- 
duced Mr.  Beauchamp  Towers  to  carry  out  his  celebrated  re- 
searches on  the  friction  of  lubricated  journals,  the  results  of 
which  research  certainly  claim  notice  as  one  of  the  most  important 
steps  in  mechanical  science." 

Lord  Rayleigh  has  said  :— 

"The  present  development  of  electricity  on  a  large  scale  de- 


GERMANY  IN  THE  LEAD  275 

pends  as  much  upon  the  incandescent  lamp  as  the  dynamo.  The 
success  of  these  lamps  demands  a  very  perfect  vacuum — not  more 
than  one  millionth  of  the  normal  quantity  of  air  should  remain. 
It  is  interesting  to  recall  that  in  1865  such  vacua  were  rare  even 
in  the  laboratory  of  the  physicist.  It  is  pretty  safe  to  say  that 
these  wonderful  results  would  never  have  been  accomplished  had 
practical  applications  alone  been  in  view.  The  way  was  pre- 
pared by  an  army  of  men  whose  main  object  was  the  advancement 
of  knowledge,  and  who  could  scarcely  have  imagined  that  the 
processes  which  they  had  elaborated  would  soon  be  in  use  on  a 
commercial  scale  and  entrusted  to  the  hands  of  ordinary  work- 
men." He  adds:— "The  requirements  of  practice  react  in  the 
most  healthy  manner  upon  scientific  electricity.  Just  as  in  former 
days  the  science  received  a  stimulus  from  the  application  to 
telegraphy,  under  which  everything  relating  to  measurement  on  a 
small  scale  acquired  an  importance  and  development  for  which 
we  might  otherwise  have  had  long  to  wait,  so  now  the  require- 
ments of  electric  lighting  are  giving  rise  to  a  new  development  of 
the  art  of  measurement  on  a  large  scale,  which  cannot  fail  to 
prove  of  scientific  as  well  as  practical  importance." 

Regarding  the  territory  likely  to  yield  most  fruit  to  the  re- 
searcher, he  observes :—  "The  neglected  border  land  between  two 
branches  of  knowledge  is  often  that  which  best  repays  cultiva- 
tion ;  or,  to  use  a  metaphor  of  Maxwell's,  the  greatest  benefits 
may  be  derived  from  a  cross-fertilization  of  the  sciences." 

Why  Germany  leads  the  world  in  science  becomes  clear  when 
we  observe  her  co-ordination  of  industry  with  the  higher  educa- 
tion and  with  original  research.   Professor  Wil- 
helm  Ostwald  has  said  :— "When  the  student  in       The  Example 
Germany . has  finished  his  university  course  he  is        of  Germany. 
still  entirely  free  to  choose  between  a  scientific 
and  a  technical  career.     .     .     .     The  occupation  of  a  technical 
chemist  in  works  is  very  often  almost  as  scientific  in  its  character 
as  in  a  university  laboratory.     .     .     .     The  organization  of  the 
power  of  invention  in  manufactures  on  a  large  scale  in  Germany 
is,  as  far  as  I  know,  unique  in  the  world's  history,  and  is  the  very 
marrow  of  our  splendid  triumphs.     Each  large  works  has  the 
greater  part  of  its  scientific  staff— and  there  are  often  more  than 


276  ORIGINAL  RESEARCH 

a  hundred  doctors  of  philosophy  in  a  single  manufactory— oc- 
cupied not  in  the  management  of  the  manufacture,  but  in  making 
inventions.  The  research  laboratory  in  such  works  is  only  dif- 
ferent from  one  in  a  university  from  its  being  more  splendidly 
and  sumptuously  fitted.  I  have  heard  from  the  business  managers 
of  such  works  that  they  have  not  infrequently  men  who  have 
worked  for  four  years  without  practical  success ;  but  if  they  have 
known  them  to  possess  ability  they  keep  them  notwithstanding, 
and  in  most  cases  with  ultimate  success  sufficient  to  pay  all  ex- 
penses." 

In  1902  Mr.  Andrew  Carnegie,  with  a  gift  of  ten  million  dol- 
lars, founded  in  Washington  the  Carnegie  Institution  for  Original 

Research.     Its  president  is  Dr.  R.  S.  Wood- 
Mr.  Carnegie's      ward,  formerly  of  Columbia  University,  New 
Aid  to  Original      York.    One  of  its  first  enterprises  was  to  estab- 
Research.  Hsh    at    Cold    Spring   Harbor,    New    York,    a 

station  for  experimental  evolution  directed  by 
Dr.  Charles  B.  Davenport.  Here  will  be  extended  the  remarkable 
experiments  of  Dr.  Hugo  de  Vries,  of  Amsterdam,  who  dis- 
covered that  the  large-flowered  evening  primrose  suddenly  gives 
rise  to  new  species.  Other  experiments  are  in  progress  with 
regard  to  the  variability  of  insects,  the  hybridization  of  plants 
and  animals.  A  marine  biological  laboratory  has  been  established 
at  Tortugas,  Florida ;  and  a  desert  botanical  laboratory  at  Tucson, 
Arizona.  In  its  grants  for  widely  varied  purposes  the  policy  of 
the  Institution  is  clear :  only  those  inquiries  are  aided  which  give 
promise  of  fruit,  and  in  every  case  the  grantee  requires  to  be 
a  man  of  proved  ability,  care  being  taken  not  to  duplicate  work 
already  in  hand  elsewhere,  or  to  essay  tasks  of  an  industrial 
character.  Experience  has  already  shown  it  better  to  confine 
research  to  a  few  large  projects  rather  than  to  aid  many  minor 
investigations  with  grants  comparatively  small. 

One  branch  of  the  work  reminds  us  of  Mr.  Carnegie's  method 
in  establishing  public  libraries— the  supplementing  of  local  public 
spirit  by  a  generous  gift.  In  many  cases  a  university  or  an  ob- 
servatory launches  an  inquiry  which  soon  broadens  out  beyond 
the  range  of  its  own  small  funds ;  then  it  is  that  aid  from  the  Car- 
negie Institution  brings  to  port  a  ship  that  otherwise  might  re- 


DR.  R.  S.  WOODWARD, 
PRESIDENT,  CARNEGIE  INSTITUTION,  WASHINGTON,  D.  C. 


THE  CARNEGIE  INSTITUTION       277 

main  at  sea  indefinitely.  Let  a  few  typical  examples  of  this  kind 
be  mentioned :— Dudley  Observatory,  Albany,  New  York,  and 
Lick  Observatory,  California,  have  received  aid  toward  their  ob- 
servations and  computations ;  Yerkes  Observatory,  Wisconsin,  has 
been  helped  in  measuring  the  distances  of  the  fixed  stars.  Among 
other  investigations  promoted  have  been  the  study  of  the  rare 
earths  and  the  heat-treatment  of  some  high-carbon  steels.  The 
adjacent  field  of  engineering  has  not  been  neglected :  funds  have 
been  granted  for  experiments  on  ship  resistance  and  propulsion, 
for  determining  the  value  of  high  pressure  steam  in  locomotive 
service.  In  geology  an  investigation  of  fundamental  principles 
has  been  furthered,  as  also  the  specific  problem  of  the  flow  of 
rocks  under  severe  pressure.  In  his  remarkable  inquiry  into  the 
economy  of  foods,  Professor  W.  O.  Atwater,  of  Wesleyan  Uni- 
versity, Middletown,  Connecticut,  has  had  liberal  help.  In  the 
allied  science  of  preventive  medicine  a  grant  is  advancing  the 
study  of  snake  venoms  and  defeating  inoculations. 

At  a  later  day  the  Institution  may  possibly  adopt  plans  recom- 
mended by  eminent  advisers  of  the  rank  of  Professor  Simon 
Newcomb,  who  points  out  that  analysis  and  generalization  are 
to-day  much  more  needed  than  further  observations  of  a  routine 
kind.  He  has  also  had  a  weighty  word  to  say  regarding  the  de- 
sirability of  bringing  together  for  mutual  attrition  and  discussion 
men  in  contiguous  fields  of  work,  who  take  the  bearings  of  a 
great  problem  from  different  points  of  view. 

Speaking  of  the  study  of  human  life  and  society,  Professor 
Karl  Pearson  is  clear  that  both  thorough  training  as  well  as  sound 
theories  are  needed  if  research  is  to  be  fruitful.  In  the  course  of 
a  letter  to  the  Carnegie  Institution,  he  says : — "Biological  and 
sociological  observations  in  too  many  cases  are  of  the  lowest  grade 
of  value.  Even  where  the  observers  have  begun  to  realize  that 
exact  science  is  creeping  into  the  biological  and  sociological  fields 
they  have  not  understood  that  a  thorough  training  in  the  new 
methods  is  an  essential  preliminary  for  effective  work,  even  for 
the  collection  of  material.  They  have  rushed  to  measure  or  count 
every  living  form  they  could  hit  on,  without  having  planned  at 
the  start  the  conceptions  and  ideas  that  their  observations  were 
intended  to  illustrate.  I  doubt  whether  even  a  small  proportion 


278  ORIGINAL  RESEARCH 

of  the  biometric  data  being  accumulated  in  Europe  and  America 
could  by  any  amount  of  ingenuity  be  made  to  provide  valuable 
results,  and  the  man  capable  of  making  it  yield  them  would  be 
better  employed  in  collecting  and  reducing  his  own  material." 

Professor  Edward  C.  Pickering,  Director  of  the  Harvard  Ob- 
servatory, has  suggested  that  astronomers  the  world  over  resolve 
themselves  into  a  committee  of  the  whole  for  the  attack  of  great 
questions,  the  work  to  be  duly  parcelled  out  among  the  observa- 
tories best  placed  and  equipped  for  specific  tasks,  to  the  end  that 
repetition  be  avoided  and  a  single,  comprehensive  plan  be  pur- 
sued. Not  only  in  astronomy  but  in  every  field  of  science  such 
concerted  attack  would  have  great  value.  In  engineering,  for 
example,  there  are  questions  as  to  the  durability  of  steels  and  other 
building  materials,  which  when  investigated  would  yield  rich 
harvests  to  every  practicing  engineer  on  the  globe.  It  may  be  ex- 
pected that  in  effecting  co-ordinations  of  this  kind  the  Carnegie 
Institution  will  play  a  notable  part  in  the  science  of  the  twentieth 
century. 


CHAPTER  XX 
OBSERVATION 

What  to  look  for  .  .  .  We  may  not  see  what  we  do  not  expect  to  see  .  .  . 
Lenses  reveal  worlds  great  and  small  otherwise  unseen  .  .  .  Observers 
of  the  heavens  and  of  seashore  life  .  .  .  Collections  aid  discovery  .  .  . 
Happy  accidents  turned  to  profit  .  .  .  Value  of  a  fresh  eye  .  .  .  Popular 
beliefs  may  be  based  on  truth  .  .  .  An  engineer  taught  by  a  bank  swal- 
low. 

A  BILITY  to  observe  is  an  unfailing  mark  of  an  inventor  or 
1T\.  discoverer :  it  is  quite  as  much  a  matter  of  the  mind  as  of 
the  eye.  A  botanist,  keenly  alive  to  varieties  of  hue,  of  form  in 
leaves,  tendrils,  and  petals  may  not  give  a  second  glance  to 
stratifications  which  rivet  the  gaze  of  a  geologist  for  hours  to- 
gether. Each  sees  what  he  knows  about,  what  he  is  interested  in, 
what  he  brings  the  power  and  desire  to  see.  When  Faraday  was 
asked  to  witness  an  experiment  he  always  said :  "What  is  it  that 
I  am  to  look  for  ?"  He  knew  the  importance  of  concentrating  his 
attention  on  the  very  bull's  eye  of  a  target. 

How  much  goes  to  sound  observing  is  thus  stated  by  John 
Stuart  Mill,— "The  observer  is  not  he  who  merely  sees  the  thing 
which  is  before  his  eyes,  but  he  who  sees  what  parts  the  thing  is 
composed  of.  One  person,  from  inattention,  or  attending  only  in 
the  wrong  place,  overlooks  half  of  what  he  sees ;  another  sets 
down  much  more  than  he  sees,  confounding  it  with  what  he 
imagines,  or  with  what  he  infers ;  another  takes  note  of  the  kind 
of  all  the  circumstances,  but  being  inexpert  in  estimating  their 
degree,  leaves  the  quantity  of  each  vague  and  uncertain ;  another 
sees  indeed  the  whole,  but  makes  such  an  awkward  division  of  it 
into  parts,  throwing  into  one  mass  things  which  require  to  be 
separated,  and  separating  others  which  might  more  conveniently 

270 


280  OBSERVATION 

be  considered  as  one,  that  the  result  is  much  the  same,  sometimes 
even  worse  than  if  no  analysis  had  been  attempted  at  all." 

How  an  explorer  of  ability  may  witness  a  new  fact  without 
realizing  that  it  points  to  a  great  industry,  is  shown  in  the  case 
of  Lord  Dundonald.  In  1782,  or  thereabout,  near  Culross  Abbey 
in  Scotland,  he  built  a  tar-kiln.  Noticing  the  inflammable  na- 
ture of  a  vapor  arising  during  the  distillation  of  tar,  the  Earl,  by 
way  of  experiment,  fitted  a  gun-barrel  to  the  eduction  pipe  lead- 
ing from  the  condenser.  On  applying  fire  to  the  muzzle,  a  vivid 
light  blazed  forth  across  the  waters  of  the  Frith,  distinctly  visible 
on  the  opposite  shore.  Soon  afterward  the  inventor  visited  James 
Watt  at  Handsworth,  near  Birmingham,  and  told  him  about  the 
gas-lighting  at  the  kiln,  but  his  host  paid  no  attention  to  the 
matter.  His  assistant,  William  Murdock,  however,  was  impressed 
by  the  story,  and  some  years  later  applied  gas  to  the  illumination 
of  the  Soho  works  where  Watt's  engines  were  built.  This  was 
the  beginning  of  gas-lighting  as  a  practical  business. 

Professor  Adam  Sedgwick,  of  Cambridge  University,  famous 
as  a  geologist,  and  Charles  Darwin  once  took  an  excursion  in 
Wales  amid  markings  of  extraordinary  interest  which  neither  of 
them  noticed.  Darwin  tells  us :  "I  had  a  striking  instance  of  how 
easy  it  is  to  overlook  phenomena,  however  conspicuous,  before  they 
have  been  observed  by  any  one.  We  spent  many  hours  at  Cwm 
Idwal,  examining  the  rocks  with  extreme  care,  as  Sedgwick  was 
anxious  to  find  fossils  in  them,  but  neither  of  us  saw  a  trace  of 
the  wonderful  glacial  phenomena  all  around  us ;  we  did  not  notice 
the  plainly  scored  rocks,  the  perched  boulders,  the  lateral  and 
terminal  moraines,  yet  these  phenomena  are  so  conspicuous  that, 
as  I  declared  in  a  paper  published  many  years  afterward,  a  house 
burnt  down  by  fire  could  not  tell  its  story  more  plainly  than  did 
this  valley.  If  it  had  been  filled  with  a  glacier,  the  phenomena 
would  have  been  less  distinct  than  they  now  are."  At  a  later  day 
when  Darwin's  powers  of  observation  had  become  acute  in  the 
highest  degree,  he  noticed  a  bird's  feet  covered  with  dirt.  Rather 
a  common  fact,  not  worth  dwelling  on,  earlier  observers  had  sup- 
posed. Not  so  thought  Darwin.  He  carefully  washed  the  bird's 
feet,  and  planting  the  removed  solids  he  was  rewarded  with  sev- 
eral strange  plants  brought  from  afar  by  his  winged  visitor. 


ORANGE  GROVES  SAVED     281 

A  cousin  to  Charles  Darwin,  Francis  Galton,  is  an  investigator 
of  eminence.  In  a  study  of  visual  memory,  a  faculty  in  which 
observation  bears  its  best  fruits,  he  says  :— 

"It  is  a  mistake  to  suppose  that  sharp  sight  is  accompanied  by 
clear  visual  memory.  I  have  not  a  few  instances  in  which  the  in- 
dependence of  the  two  faculties  is  emphatically  commented  upon ; 
and  I  have  at  least  one  clear  case  where  great  interest  in  outlines 
and  accurate  apprehension  of  straightness,  squareness,  and  the 
like,  is  unaccompanied  by  the  power  of  visualizing." 

A  new  instrument,  machine  or  engine  is  imagined  by  its  creator 
long  before  it  takes  actual  form ;  everything  he  sees  that  will  be  of 
help  he  builds  at  once  into  his  design,  everything  else,  however 
interesting  in  itself,  he  passes  with  a  heedless  eye. 

"If  we  think  birds,  we  shall  see  birds  wherever  we  go,"  says 
John  Burroughs.    An  observer  faithful  and  accurate  in  noticing 
birds  and  beasts,,  rocks  and  leaves,  may  come  at 
last  upon  a  flower  which  opens  a  sphere  of        Think  Birds 
knowledge  wholly  new,   as  when  the   round-       and  You  Shall 
leaved  sun-dew  was  first  observed  to  entrap          Scc  Birds, 
and  feed  upon  insects.     Much,  also,  depends 
upon  comparisons  such  as  occur  only  to  a  mind  at  once  broad  and 
alert.    One  may  notice  in  spring  and  early  summer  a  few  leaves 
growing  directly  from  the  trunk  of  a  tree,  sometimes  near  the 
ground.    In  maples  these  leaves  are  decidedly  narrower  than  those 
growing  from  branches  in  the  usual  way,  and  they  often  have  a 
reddish  tinge.     Comparing  a  variety  of  such  leaves  with  fossil 
impressions  of  allied  species,  Professor  Robert  T.  Jackson  of 
Boston  came  upon  an  interesting  discovery.    He  found  that  these 
sporadic  leaves  closely  resemble  those  borne  by  the  remote  an- 
cestors of  our  present  trees :  they  are  the  lingering  reminders  of  a 
far  distant  day. 

An  observation  equally  keen  saved  the  orange  groves  of  Cali- 
fornia from  destruction  by  the  fluted  scale  insect.  In  1890,  or 
thereabout,  the  orange  growers  in  their  extremity  sought  the  ad- 
vice of  Professor  C.  V.  Riley,  entomologist  to  the  Department  of 
Agriculture  at  Washington.  He  asked:  "Where  did  the  pest 
come  from?"  "Australia,"  was  the  answer.  "Is  it  much  of  a 
nuisance  there?"  "Not  particularly."  "Then  what  keeps  it 


282  OBSERVATION 

down,  what  preys  upon  it?"  "Nothing  specially,"  was  the  re- 
sponse. Dissatisfied  with  this  answer,  Professor  Riley  sent  to 
Australia  a  trained  entomologist  and  acute  observer,  Mr.  Albert 
Koebele,  who  gathered  various  insects  noticed  as  preying  upon 
the  fluted  scale.  Distributing  these  upon  his  arrival  in  California 
he  was  fortunate  enough  to  find  that  one  of  his  assisted  emi- 
grants, a  lady  bird,  Vedalia  cardinalis,  fed  so  ravenously  upon 
the  fluted  scale  as  to  restrict  its  ravages  to  quite  moderate 
proportions. 

It  was  an  equally  disciplined  eye  which  in  the  laboratory  first 
noticed  that  air  is  non-conducting  until  traversed  by  an  X-ray, 
when  it  becomes  conducting  in  a  noteworthy  degree.  The  field 
of  radio-activity,  at  which  we  have  glanced  in  this  book,  owes  its 
cultivation  to  observers  keen  to  note  phenomena  utterly  unlike 
those  before  dwelt  upon  by  the  human  eye.  Often  close  ob- 
servers learn  what  would  never  be  imagined  as  possible :  in  rifle- 
making  the  tendency  of  the  drills,  which  revolve  nearly  a  thou- 
sand times  a  minute,  to  follow  the  axial  line  in  a  revolving  bar 
is  a  fact  which  may  be  accounted  for  after  observation,  but  which 
no  one  would  predict. 

One  day  on  the  Glasgow  and  Ardrossan  Canal  a  spirited  horse 
took  fright;  it  was  then  observed,  with  astonishment,  that  a  boat, 
the  "Raith,"  to  which  it  was  attached,  for  all  its  increased  speed, 
went  through  the  water  with  less  resistance  than  before.  The 
vessel  rode  on  the  summit  of  a  wave  of  its  own  creation  with  this 
extraordinary  effect.  The  "Raith,"  said  Mr.  Scott  Russell, 
"weighed  10,239  pounds,  requiring  a  force  of  112  pounds  to  drag 
it  at  4.72  miles  an  hour;  275  pounds  at  6.19  miles  an  hour,  and 
but  268^  pounds  at  10.48  miles  per  hour."  Thus  paradoxically 
was  reversed  the  rule  that  the  resistance  of  a  vessel  increases 
rapidly  as  she  is  moved  through  the  water.  Mr.  Russell  added : 
— "Some  time  since  a  large  canal  in  England  was  closed  against 
general  trade  by  want  of  water,  drought  having  reduced  the 
depth  from  12  to  5  feet.  It  was  then  found  that  the  motion  of 
the  light  boats  was  more  easy  than  before ;  the  cause  was  obvious. 
The  velocity  of  the  wave  was  so  much  reduced  by  the  diminished 
depth,  that,  instead  of  remaining  behind  the  wave,  the  vessels 
rode  on  its  summit." 


MISSISSIPPI  JETTIES  283 

One  of  the  most  difficult  problems  ever  solved  by  an  American 
engineer  was  the  making  navigation  safe  for  vessels  of  fairly 
deep  draft  in  the  lower  branches  of  the  Mis- 
sissippi. The  difficulties  were  overcome  by  The  Mississippi 
James  B.  Eads,  of  St.  Louis,  in  his  system  of 
jetties.  He  remarked,  says  his  biographer, 
Mr.  Louis  How,  that  other  things  being  equal,  the  amount  of 
sediment  which  a  river  can  carry  is  in  direct  proportion  to  its 
velocity.  When,  for  any  reason,  the  current  becomes  slower  at 
any  special  place,  it  drops  part  of  its  burden  of  sediment  at  that 
place,  and  when  it  becomes  faster  again  it  picks  up  more.  Now, 
one  thing  that  makes  a  river  slower  is  an  increase  of  its  width, 
because  then  there  is  more  f rictional  surface ;  and  contrariwise, 
one  of  the  things  that  makes  it  faster  is  a  decrease  of  its  width. 
Narrow  the  Mississippi  then,  at  its  mouth,  said  Eads,  and  it  will 
become  swifter  there,  and  consequently  will  remove  its  soft  bot- 
tom by  picking  up  the  sediment  (of  which  it  will  then  hold  much 
more),  and  by  carrying  it  out  to  the  gulf,  to  be  lost  in  deep  water 
and  swept  away  by  currents,  you  will  have  your  deep  channel. 
In  other  words,  if  you  give  the  river  some  assistance  by  keeping 
its  current  together,  it  will  do  all  the  necessary  labor  and  scour 
out  its  own  bottom.  This  sound  reasoning,  based  upon  observa- 
tion as  sound,  was  duly  embodied  in  a  series  of  jetties  which  have 
proved  successful. 

Such  a  river  as  the  Mississippi  taking  its  source  through  an 
alluvial  plain,  has  bends  which  go  on  increasing  by  the  wearing 
away  of  the  outer  banks,  and  the  deposition  of 
mud,  sand  and  gravel  on  the  inner  bank.  In  Observation 
1876  at  the  Glasgow  meeting  of  the  British 
Association  for  the  Advancement  of  Science, 
Professor  James  Thomson  showed  a  model  which  made  the 
phenomena  of  the  case  perfectly  clear.  A  stream  eight  inches 
wide  and  less  than  two  inches  deep,  flowed  round  a  bend.  As  it 
turned  this  bend  the  water  exerted  centrifugal  force,  while  a  thin 
layer  of  the  water  at  the  bottom,  representing  a  similar  layer  close 
to  a  river-bed,  was  retarded  by  its  friction  with  the  remainder  of 
the  stream,  exerting  less  centrifugal  force  than  like  portions  of 
the  larger  body  of  water  flowing  over  it  farther  away  from  the 


284  OBSERVATION 

bottom.  Consequently  the  bottom  layer  flowed  in  obliquely 
across  the  channel  toward  the  inner  bank ;  rising  up  in  its  retarded 
motion  betwixt  the  fast  flowing  water  it  protected  the  inner  bank 
from  scour.  At  the  same  time  this  retarded  current  brought  with 
it  sand  and  other  detritus  from  the  bottom,  duly  deposited  along 
the  inner  bank  of  the  stream. 

The  powers  of  the  eye,  acute  as  they  are,  have  narrow  limits; 
inestimable  therefore  is  the  value  of  the  microscope,  the  telescope 
and  the  camera  which  bring  to  view  uncounted 
ima£es  otherwise  unseen.  Let  us  remark  how 
Observation.  *n  tne  eal"ly  days  of  instrumental  aids  a  great 
observer  just  missed  noting  a  phenomenon  of 
utmost  importance,— the  black  lines  of  the  solar  spectrum,  upon 
which  Fraunhofer,  an  optician  of  Munich,  based  his  spectroscope. 
In  sending  a  solar  beam  through  a  lens  and  a  prism  Sir  Isaac 
Newton  admitted  the  rays  through  an  oblong  slit  at  times  as 
narrow  as  one  twentieth  of  an  inch.  He  saw  the  familiar  colors, 
from  red  to  violet,  and  nothing  more.  Even  with  a  crown  lens, 
such  as  he  probably  used,  four  lines  distinctly  appear ;  that  is,  they 
appear  to-day,  to  an  observer  who  is  looking  for  them.  In  1802 
these  lines  were  observed,  as  far  as  we  know,  for  the  first  time 
on  record,  by  Dr.  Wollaston,  who  drew  six  of  them  in  a  diagram 
accompanying  a  paper  in  the  Philosophical  Transactions.  Four 
of  these  lines  he  regarded  as  boundaries  of  the  colors  of  the 
spectrum;  of  the  other  two  lines  he  attempted  no  explanation. 
He  used  prisms  of  various  materials  but  found  no  alteration  in 
the  lines  while  he  studied  a  sunbeam.  When  he  employed  candles 
or  an  electric  light  he  found  the  appearances  different,  why,  he 
could  not  undertake  to  explain.  In  1814,  Fraunhofer  observed 
these  lines  in  detail,  mapped  them,  and  proved  that  they  identified 
elements  long  known  to  chemists.  As  he  built  his  spectroscope  he 
gave  the  chemist,  the  physicist  and  the  astronomer  an  instrument 
of  research  worthy  a  place  beside  either  the  microscope  or  the 
telescope. 

Dr.  Wollaston,  in  1802,  as  we  have  seen  stood  upon  the 
threshold  of  spectroscopy  without  knowing  it.  During  the  same 
year  he  performed  an  experiment  which  took  him  into  the  field 
of  photography  without  his  recognizing  the  possibilities  of  that 


A  DOUBLE  STAR  DETECTED        285 

wonderful  art.  He  took  paper  which  had  been  dipped  in  muriate 
of  silver  and  caught  on  its  surface  impressions  of  the  ultra-violet 
light  in  a  solar  spectrum.  These  rays,  as  rings,  were  reflected 
from  a  thin  plate  of  air,  as  in  the  case  of  the  colors  of  thin  plates, 
at  distances  corresponding  to  their  proper  places  in  the  spectrum. 
Thus  was  established  the  close  analogy  between  rays  visible  and 
invisible,  and  by  a  method  destined  to  give  mankind  a  universal 
limner  in  light  of  all  kinds,  and  in  much  radiance  which  is  not 
luminous  at  all. 

Edward  Emerson  Barnard,  of  the  Yerkes  Observatory,  Wil- 
liams Bay,  Wisconsin,  is  in  the  first  rank  of  living  astronomers. 
Among  his  many  discoveries  the  most  remark- 
able is  that  of  the  fifth  satellite  of  Jupiter  at  TWO  Observers 
the  Lick  Observatory.  His  early  work  at  the  of  the  Skies. 
Vanderbilt  Observatory,  Nashville,  gave  full 
promise  of  his  later  achievements.  One  evening  in  November, 
1883,  ne  was  observing  an  occultation  of  the  well-known  star 
Beta  Capricorni  by  the  moon.  He  had  patiently  waited  for  his 
opportunity;  such  an  occultation  is  best  seen  when  the  moon  is 
a  small  crescent,  the  star  disappearing  at  the  dark  curve  of  the 
moon  where  its  beams  do  not  overpower  the  feeble  stellar  ray. 
When  the  moon  passes  between  the  eye  and  a  fixed  star,  the  dis- 
appearance of  the  star  is  instantaneous.  At  the  distance  from 
which  we  look  at  it  the  star  is  a  point  only,  and  as  the  moon  has 
no  atmosphere,  the  instant  the  edge  of  the  lunar  surface  touches 
the  line  joining  the  eye  of  the  observer  with  the  star,  it  vanishes 
from  sight.  When  the  moon  passed  in  front  of  Beta  Capricorni 
Mr.  Barnard  noticed  that  instead  of  disappearing  at  once,  there 
was  a  sudden  partial  diminution  of  the  light  of  the  star,  then  a 
total  extinction  of  the  remaining  point.  The  interval  between 
the  diminution  and  complete  extinction  of  the  light  occupied  only 
a  few  tenths  of  a  second,  but  it  was  long  enough  to  put  his  keen 
mind  upon  inquiry.  Mr.  Barnard  in  an  astronomical  journal 
called  attention  to  the  phenomenon  and  suggested  that  instead  of 
there  being  only  one  star,  as  formerly  supposed,  there  were  really 
two  stars  so  close  together  that  in  an  ordinary  six-inch  telescope, 
such  as  he  had  used,  they  appeared  to  be  one.  He  inferred  also 
that  one  of  the  pair  must  be  a  good  deal  brighter  than  the  other, 


286  OBSERVATION 

because  at  the  beginning  the  change  in  brightness  was  less  than 
at  the  end.  This  surmise  was  soon  afterward  fully  verified  by 
Mr.  S.  W.  Burnham  with  the  eighteen  and  one  half  inch  equa- 
torial of  the  Dearborn  Observatory  at  Chicago,  revealing  a  close 
and  unequal  double  star  which  would  have  remained  unresolved 
had  he  used  a  less  powerful  instrument. 

This  Sherburne  Wesley  Burnham  is  the  most  successful  dis- 
coverer of  double  stars  who  has  ever  lived.  "The  extreme  acute- 
ness  of  vision/'  says  Professor  John  Fraser,  "which  enables  one 
to  prosecute  such  research  with  the  highest  success  is  a  very  rare 
gift;  and  the  discovery  of  close  doubles,  as  in  his  case,  is  its 
severest  test.  To  measure  a  star— that  is,  to  ascertain  by  means 
of  the  micrometer  the  distance  and  position  angle  of  the  com- 
panion with  reference  to  the  principal  star— is  one  thing,  and  to 
find  new  and  close  doubles  is  a  very  different  thing.  Baron 
Dembowski,  the  most  noted  measurer  of  double  stars,  had  no  suc- 
cess as  a  discoverer,  and  confessed  his  inability  to  find  new 
doubles.  When,  however,  a  new  double  had  been  found  by  an- 
other observer,  and  the  distance  and  position  angle  of  the  com- 
panion approximately  estimated,  he  could  readily  find  and  ac- 
curately measure  it.  When  Mr.  Asaph  Hall,  in  1877,  had  found 
the  two  satellites  of  Mars  and  described  their  positions,  it  was  not 
difficult  for  any  astronomer  who  had  access  to  a  large  Clark  tele- 
scope to  find  them  and  see  all  that  Mr.  Hall  had  seen.  The  whole 
difficulty  was  in  seeing  them  for  the  first  time.  Besides  the 
ability  to  see  a  difficult  object,  there  is  required  an  intelligence 
and  experimental  knowledge  of  the  subject,  which  are  as  rare  as 
the  visual  faculty  itself.  Some  of  the  lower  animals  have  more 
acute  vision  than  human  beings ;  but  they  do  not  know  all  they 
see,  or  understand  relations  to  other  facts.  They  have  plenty  of 
sight,  but  they  lack  insight.  Mr.  Burnham's  powers  in  both  these 
respects  is  extraordinary." 

At  the  Cape  of  Good  Hope  Observatory  remarkable  observa- 
tions of  double  stars  have  been  recorded.  Sir  David  Gill,  the 
director,  says :— "At  the  Cape  Observatory,  as  has  always  been 
the  case  elsewhere,  the  subject  of  double  star  measurement  on 
any  great  scale  waited  for  the  proper  man  to  undertake  it.  There 
is  no  instance,  so  far  as  I  know,  of  a  long  and  valuable  series  of 


AN  EYE  .OF  VARIED  POWERS       287 

double  star  discovery  and  observation  made  by  a  mere  assistant 
acting  under  orders.  It  is  a  special  faculty,  an  inborn  capacity, 
a  delight  in  the  exercise  of  exceptional  acuteness  of  eyesight 
and  natural  dexterity,  coupled  with  the  gift  of  imagination  as  to 
the  true  meaning  of  what  he  observes,  that  imparts  to  the  ob- 
server the  requisite  enthusiasm  for  double  star  observing.  No 
amount  of  training  or  direction  could  have  created  the  Struves, 
a  Dawes  or  a  Dembowski.  The  great  double  star  observer  is 
born,  not  made,  and  I  believe  that  no  extensive  series  of  double 
star  discovery  and  measurement  will  ever  emanate  from  a  regular 
observatory  through  successive  directorates  unless  men  are 
specially  selected  who  have  previously  distinguished  themselves 
in  that  field  of  work,  and  who  were  originally  driven  to  it  from 
sheer  compulsion  of  inborn  taste." 

It  is  sometimes  said  that  the  faculty  of  observation  is  a  special 
gift  with   limitations,   that  the  naturalist   sees  bones,    feathers, 
shells  because  he  is  looking  for  them,  while 
the  armorer  or  the  engineer  but  seldom  gives        *r>be  Eye  of  a 
a  second  glance  to  anything  but  guns,  girders,         Naturalist, 
or  machinery. 

To  this  rule  we  find  striking  exceptions.  Edward  S.  Morse, 
of  Salem,  Massachusetts,  is  the  foremost  American  expert  in 
Japanese  pottery.  As  a  youth  he  was  a  railroad  draughtsman  in 
Portland,  Maine,  where  his  ambidexterity  with  the  pencil  and  his 
discoveries  in  natural  history  brought- him  to  the  notice  of  Louis 
Agassiz.  As  a  boy  he  was  greatly  interested  in  the  shells  of  his 
native  State;  before  he  left  school  he  had  discovered  and  de- 
scribed a  new  species  of  land  snail,  Helix  asteriscus,  which  the 
older  naturalists  had  regarded  as  the  young  state  of  another  and 
well-known  species.  At  the  same  time  he  determined  the  distinct 
character  of  a  most  minute  species,  Helix  minutissitna,  which 
had  been  described  as  such  thirty  years  before,  but  which  the 
later  authorities  had  believed  to  be  the  young  of  another  species. 
This  faculty  for  discrimination  led  him  to  demonstrate  a  new 
bone  in  the  ankle  of  birds  which  Huxley,  and  others,  had  sup- 
posed to  be  a  process  and  not  a  separate  bone.  This  discovery 
added  another  to  the  many  reptilian  characters  which  have  been 
disclosed  in  the  anatomy  of  birds.  He  also  established  beyond 


288  OBSERVATION 

question  that  the  brachiopods,  always  beliered  to  be  mollusks,  are 
not  mollusks  at  all,  but  are  related  to  the  worms.  In  Mr.  Morse's 
case  we  have  either  a  man  with  a  universal  power  of  observation, 
or  enjoying  distinct  faculties  of  perception,  each  usually  appear- 
ing alone  in  an  observer.  Noticing  a  Japanese  shooting  a  bow  and 
arrow  one  day  he  took  up  the  study  of  the  attitude  of  the  hand 
in  pulling  the  bow.  His  memoir  on  this  subject,  with  illustra- 
tions, has  attracted  world-wide  interest.  Pursuing  this  theme 
he  examined  an  ancient  object  of  bronze  having  three  prongs, 
labeled  as  a  bow-puller  in  European  museums,  showing  that  it 
had  no  relation  whatever  with  the  bow.  Keenly  susceptible  to 
the  beauty  and  variety  of  roofing  tiles  in  Europe  and  the  East, 
he  has  for  the  first  time  given  them  classification,  and  shown 
their  ethnological  significance.  While  teaching  natural  history 
at  the  University  of  Tokio  he  brought  together  the  Japanese  pot- 
tery now  exhibited  at  the  Museum  of  Fine  Arts  in  Boston,  unsur- 
passed as  a  collection  in  the  world.  His  eye  was  as  sharp  in 
reading  a  potter's  mark,  however  worn  and  blurred,  as  when  as 
a  boy  in  Maine  he  defined  minute  species  of  land  shells. 

Altogether  commendable  is  the  spirit  which  leads  a  boy  or  girl 

to  collect  and  arrange  shells,  common  wildflowers,  seaweeds,  and 

the  diverse  minerals  brought  to  light  in  a  rail- 

The  Value  of  d    cutti  What    •      thus    gathered,    COm- 

Collections.  s 

pared,  and  studied  will  leave  a  much  deeper 

impression  on  the  memory  than  what  is  seen  for  a  moment  in  a 
museum  or  a  public  garden.  And  yet,  to  the  profound  student 
the  museum  is  indispensable:  he  gives  weeks  or  months  to  the 
contents  of  its  cases,  supplementing  what  he  has  learned  in  the 
field,  by  the  seashore,  in  the  woods.  Take,  for  example,  pro- 
tective resemblances,  one  of  the  most  fascinating  provinces  of 
natural  history.  Here  is  a  hornet  clear-wing  moth.  What  has 
made  it  look  like  a  wasp  ?  Both  share  the  same  field  of  life,  and 
while  the  wasp  does  not  prey  on  the  moth  or  in  any  perceptible 
way  compete  with  it,  the  two  insects  have  a  vital  bond.  In  its 
sting  the  wasp  has  so  formidable  and  thoroughly  advertised  a 
weapon  that  by  closely  resembling  the  wasp  the  moth,  though 
stingless,  is  able  to  live  on  its  neighbor's  reputation,  and  escape 


PROTECTIVE  RESEMBLANCES       289 

attack  from  the  birds  and  insects  which  would  devour  it  if  they 
did  not  fear  that  it  is  a  stinging  wasp.  So  far  is  the  resemblance 
carried  that  when  the  moth  is  caught  in  the  hand  it  curves  its 
body  with  an  attitude  so  wasplike  as  seriously  to  strain  the  nerves 
of  its  captor. 

How  came  about  so  elaborate  a  masquerade?  At  first,  ages 
ago,  there  was  a  faint  likeness  between  the  moth  and  the  wasp; 
any  moth  in  which  that  likeness  was  unusually  decided  had  there- 
in an  advantage  and  tended  to  be  in  some  measure  left  alone  by 
enemies.  In  thus  escaping  it  could  transmit  in  an  ever-increasing 
degree,  its  peculiarities  of  form  and  hue  to  its  progeny,  until  in 
the  rapid  succession  of  insect  generations,  amid  the  equally  rapid 
destruction  of  comparatively  unprotected  moths,  the  present 
striking  similarity  arose.  Instances  of  this  kind  abound,  form- 
ing some  of  the  most  attractive  exhibits  in  the  American  Museum 
of  Natural  History  of  New  York,  and  other  great  museums. 
Mr.  W.  H.  Bates,  who  first  explained  these  resemblances,  did  so 
as  the  result  of  comparing  many  various  examples  preserved  in 
his  cabinets  at  home,  although,  of  course,  his  memory  of  habits 
observed  in  the  field  was  indispensable.  His  ample  collections 
enabled  him  to  bring  into  view  at  once  many  captures  separated 
by  wide  intervals  of  time  and  space.  It  was  the  opportunity  thus 
afforded  of  taking  a  comprehensive  survey  of  resemblances  as  a 
whole  that  led  him  to  think  out  the  underlying  reason. 

Accident  has  played  a  noteworthy  part  in  both  discovery  and 
invention.     Nathaniel  Hayward  long  ago  remarked  that  sulphur 
deprives  rubber  of  stickiness.     Charles  Good- 
year one  day  combined  some  rubber  and  sul-         Accidental 
phur  by  way  of  experiment ;  quite  by  accident 
he  overturned  part  of  the  mixture  upon  a  hot  stove.    He  saw  in 
a  moment  that  heat  is  essential  to  make  rubber  insensible  to  both 
heat  and  cold :  he  had  indeed  discovered  vulcanization.     Exam- 
ples of  this  kind  abound  in  the  history  of  every  art.     As  far 
afield  as  the  war  on  insect  pests  in  France  a  priceless  discovery 
was  hit  upon  unsought  a  few  years  ago.    One  autumn  the  vines 
were  still  suffering  from  phylloxera  when  a  mildew  caused  by  a 
fungus  began  to  do  serious  damage  to  crops.    Through  the  spray- 


290  OBSERVATION 

ing  of  vines  with  blue-stone  to  prevent  pilfering  of  fruit,  it  was 
noticed  that  the  fungus  was  killed,  leading  to  the  most  telling 
mode  of  attack  on  many  of  the  pests  which  assail  leaves,  flowers 
and  fruit. 

James  Hargreaves  once  saw  a  spinning-wheel  overturned,  when 
both  the  wheel  and  spindle  continued  to  revolve  on  the  floor.  As 
he  observed  the  spindle  thus  changed  from  a  horizontal  to  an 
upright  position  it  occurred  to  him  that  if  a  number  of  spindles 
were  thus  placed,  side  by  side,  several  threads  might  be  spun  at 
once  instead  of  a  single  thread.  This  was  the  origin  of  the  spin- 
ning jenny;  an  invention  which  has  parallels  in  the  multiple 
drills,  the  gang-saws,  and  other  machinery  which  take  a  task 
once  executed  by  a  single  drill,  saw  or  punch,  and  simultaneously 
perform  it  with  ten,  twenty,  or  a  hundred  drills,  saws,  or  punches. 

About  thirty  years  before  Josiah  Wedgwood  laid  the  founda- 
tion of  his  future  eminence,  a  chance  observation  gave  rise  to 
improvement  in  the  earthenwares  of  Staffordshire.  A  potter 
from  Burslem,  the  centre  of  the  potteries  and  the  birthplace  of 
Wedgwood,  in  traveling  to  London  on  horseback  was  detained 
on  the  road  by  the  inflamed  eyes  of  his  horse.  Seeing  the  hostler, 
the  horse-doctor  of  those  times,  burn  a  piece  of  flint,  and,  having 
reduced  it  to  a  fine  powder,  apply  it  as  a  specific  to  the  diseased 
eyes,  it  occurred  to  the  potter  that  this  beautiful  white  powder, 
if  combined  with  the  clay  used  in  his  craft,  might  improve  the 
strength  and  color  of  his  ware.  An  experiment  succeeded,  and 
so  began  English  white  ware,  since  manufactured  on  an  immense 
scale. 

More  important  than  this  discovery  of  a  new  use  for  flint 
powder  was  the  discovery,  also  accidental,  of  electro-magnetism 
by  Professor  Oersted  of  Copenhagen.  The  incident  is  thus  re- 
lated in  a  letter  to  Michael  Faraday  from  Professor  Christian 
Hansteen : — 

"Professor  Oersted  was  a  man  of  genius,  but  he  was  a  very  un- 
happy experimenter;  he  could  not  manipulate  instruments.  He 
must  always  have  an  assistant,  or  one  of  his  auditors  who  had 
easy  hands,  to  arrange  the  experiment;  I  have  often  in  this  way 
assisted  him.  In  the  eighteenth  century  there  was  a  general 
thought  that  there  was  a  great  conformity,  and  perhaps  identity, 


DISCOVERY  OF  ELECTRO-MAGNETISM  291 

between  the  electrical  and  magnetical  forces ;  and  it  was  a  ques- 
tion how  to  demonstrate  it  by  experiments.  Oersted  tried  to  place 
the  wire  of  his  galvanic  battery  perpendicular  (at  right  angles) 
over  the  magnetic  needle,  but  remarked  no  sensible  motion.  Once, 
after  the  end  of  his  lecture,  as  he  had  used  a  strong  galvanic 
battery  to  other  experiments,  he  said,  'Let  us  now  once,  as  the 
battery  is  in  activity,  try  to  place  the  wire  parallel  with  the 
needle;'  as  this  was  done  he  was  quite  struck  with  perplexity  by 
seeing  the  needle  making  a  great  oscillation  (almost  at  right 
angles  with  the  magnetic  meridian).  Then  he  said,  'Let  us  now 
invert  the  direction  of  the  current ;'  and  the  needle  deviated  in 
the  contrary  direction.  Thus  the  great  detection  was  made ;  and 
it  has  been  said,  not  without  reason,  that  'he  tumbled  over  it  by 
accident/  He  had  not  before  any  more  idea  than  any  other  per- 
son that  the  force  should  be  transversal." 

Granting  that  many  important  discoveries  thus  come  about  in 
ways  beyond  human  foresight,  accident  alone  will  not  produce 
an  invention.  As  Dr.  Ernst  Mach  reminds  us,  in  every  such  case 
the  inquirer  is  obliged  to  take  note  of  the  new  fact,  to  recognize 
its  significance,  to  detect  the  part  it  plays,  or  can  be  made  to  play, 
in  a  new  structure,  or  in  a  novel  and  sound  generalization.  What 
he  sees  before  him,  others  also  have  seen,  perhaps  many  times; 
he  is  the  first  to  notice  it  as  it  deserves  to  be  noticed,  simply  be- 
cause he  has  an  eye  earnestly  desiring  to  behold  just  such  a  fact 
as  this  and  use  it  to  bridge  a  gap  either  in  art  or  explanation. 

Let  us  take  a  case  where  an  accident,  well  observed,  has  meant 
a  golden  discovery.  One  day  during  a  trip  on  the  Thames  in  a 
steamer  propelled  by  an  Archimedean  screw  devised  by  Francis 
Pettit  Smith,  the  propeller  struck  an  obstacle  in  the  water,  so 
that  about  one  half  of  the  length  of  the  screw  was  broken  off ;  it 
was  noticed  that  the  vessel  immediately  shot  ahead  at  a  much 
quickened  pace.  In  consequence  of  this  discovery,  a  new  short 
screw  was  fitted  to  the  vessel  and  with  this  new  propeller  the 
steamer  went  uniformly  faster  than  before. 

In  craft  built  ages  before  steamers  were  designed,  fishermen 
have  observed  that  sails  torn  in  the  middle,  if  the  rents  were  not 
too  big,  were  more  effective  than  when  new  and  whole.  What 
thus  began  in  sheer  wear,  or  accidental  damage,  is  now  imitated 


292 


OBSERVATION 


of  set  purpose.  Under  the  equator  one  may  often  see  small  craft 
whose  sails  are  matting  woven  with  large  openings,  as  the  sailors 

say  "to  let  out  the  wind."  The  mariners  of 
g!\  a  Carthegena,  St.  Thomas,  and  other  islands  of 

the  West  Indies,  know  that  a  ship  goes 
better  thus  than  if  her  sails  were  each  one  continuous  breadth 
of  canvas.  Japanese  junks  of  clipper  builds  have  sails  made  of 


Perforated  sails. 

I,  jib.    2,  stay-sail.    3,  square  sail.    4,  top  sail. 
5,  sloop  with  perforated  sails. 


vertical  breadths  laced  together  so  as  to  leave  large  apertures 
free  to  the  air.  Why  is  this  breeziness  of  structure  profitable? 
Because  against  the  concave  surface  of  an  ordinary  sail  the  wind 
rebounds  so  as  to  hinder  its  impulsive  effect;  through  an  aper- 
ture the  air  rushes  in  a  continuous  current  and  no  rebound  takes 
place.  For  a  like  reason,  and  with  similar  gain,  Chinese  rudders 
are  made  with  separated  boards  or  planks.  The  stream  of  water 
passing  through  such  a  rudder  would  exert  an  undesirable  back 
pressure  in  a  rudder  of  solid  form. 

It  would  be  interesting,  and  might  prove  gainful,  to  experiment 
with  perforated  sails  in  sail-boats,  ice-boats  and  wind-mills.  In 
large  kites,  sent  to  the  upper  air  by  meteorologists,  it  has  been 
found  helpful  to  give  the  fabric  a  few  small  perforations. 


VALUE  OF  AN  EYE  UNTIRED       293 

It  is  not  only  necessary  to  observe  if  one  would  learn,  one  must 
remember  and  compare  observations.    In  a  cycle  of  223  lunations 
all  the  motions  of  the  moon  are  repeated;  it  is 
astonishing   that   astronomers   in   Chaldea   de-        Observations 

tected  this  period,  exceeding  eighteen  years  as     Must  be  Remem- 
•  ,     1  s-\       t         .,1         i        j  f  ^1-  bered  and  Corn- 

it  does.     On  the  other  hand,  one  of  the  most     afed  m  The  Value 

striking    phenomena    of    a    solar    eclipse,    its       Of  a  jjew  Eye. 
revelation  of  the  solar  corona,  does  not  seem 
to  have  been  noticed  until  comparatively  recent  times.    The  first 
known  record  of  it  is  by  Lobatchevsky,  July  8,  1842. 

There  is  value  in  the  teaching  which  teaches  the  eye  what  to 
observe ;  at  times  there  is  gain  in  a  freshness  of  view  unwarped 
by  ideas  as  to  what  deserves  to  be  inspected  and  what  does  not. 
Dr.  Priestley,  one  of  the  founders  of  chemistry,  says: — "I  do  not 
at  all  think  it  degrading  to  the  business  of  experimental  philos- 
ophy to  compare  it,  as  I  often  do,  to  the  diversion  of  hunting, 
where  it  sometimes  happens  that  those  who  beat  the  ground  the 
most,  and  are  consequently  best  acquainted  with  it,  weary  them- 
selves without  starting  any  game,  when  it  may  fall  in  the  way 
of  a  mere  passenger ;  so  that  there  is  but  little  room  for  boasting 
in  the  most  successful  termination  of  the  chase."  True,  yet  this 
discerning  eye  will  always  be  found  beside  a  brain  of  uncommon 
force  and  sweep.  Mr.  Edwin  Reynolds,  of  Milwaukee,  as  re- 
lated in  this  book,  never  saw  a  mining  stamp  until  the  morning 
when  he  planned  a  bold  and  profitable  simplification  of  it.  Pro- 
fessor Alexander  Graham  Bell,  who  invented  the  telephone,  came 
to  his  triumph  not  as  a  disciplined  electrician,  but  as  a  student, 
under  his  father,  of  articulate  speech  and  its  transmission.  He 
has  told  me  that  had  he  known  the  obstacles  to  be  surmounted, 
he  would  never  have  begun  his  attack. 

Professor  Ernst  Abbe,  of  Jena,  who  more  than  any  other  in- 
vestigator is  to  be  credited  with  the  production  of  Jena  glass, 
was  at  the  outset  of  his  labors  quite  ignorant  of  practical  optics. 
But  he  had  a  thorough  mastery  of  mathematical  optics,  and  this 
in  due  season  enabled  him  to  revise  the  theory  of  the  microscope, 
and  to  prescribe  the  conditions  according  to  which  the  manu- 
facture of  totally  new  kinds  of  glass  should  proceed.  Every  one 
of  these  men,  every  peer  they  have  ever  had  among  the  volunteer 


294  OBSERVATION 

forces  of  research,  is  far  removed  in  native  ability,  in  plasticity 
of  mind,  from  Priestley's  "mere  passenger."  If  ignorance  by 
itself  were  the  chief  qualification  for  discovery,  science  would 
long  ago  'have  entered  upon  its  golden  age. 

Michael  Faraday,  that  consummate  observer,  held  that  at  times 
the  observations  of  comparatively  untrained  men  are  well  worth 
attention.    In  one  of  his  note-books  he  wrote: 
Any  Observation      -"Whilst  passing  through  manufactories  and 
May  Have  Value,    engaged    in    the    observance    of    the    various 
operations  of  civilized  life,  we  are  constantly 
hearing  observations  made  by  those  who  find  employment  in  these 
places,  and  are  accustomed  to  a  minute  observation  of  what  passes 
before  them  which  are  new  or  frequently  discordant  with  re- 
ceived opinions.     These  are  frequently  the  result  of  facts,  and 
though  some  are  founded  in  error,  some  on  prejudice,  yet  many 
are  true  and  of  high  importance  to  the  practical  man.     Such  of 
them  as  come  in  my  way  I  shall  set  down  here,  without  waiting 
for  the  principle  on  which  they  depend ;  and  though  three  fourths 
of  them  ultimately  prove  to  be  erroneous,  yet  if  but  one  new  fact 
is  gathered  in  a  multitude,  it  will  be  sufficient  to  justify  this  mode 
of  occupying  time." 

Often  a  conviction  widely  held  by  the  plain  people  of  a  country- 
side is  based  on  many  and  sound  observations,  long  before  a 
scientific  theory  accounts  for  the  facts.  For 
Folk  Observation  many  generations  there  was  a  saying  among 
Foreruns  Science.  German  peasants  that  when  a  storm  is  ap- 
proaching a  fire  should  be  made  in  the  stove, 
with  as  much  smoke  as  possible.  Professor  Schuster  has  shown 
that  this  saying  and  the  custom  founded  upon  it  are  rational,  as 
the  products  of  combustion  and  the  smoke  act  as  an  effective  con- 
ductor to  discharge  the  atmosphere  slowly  but  surely.  He  quotes 
statistics  showing  that  out  of  each  1000  cases  of  lightning  stroke, 
6.3  churches  and  8.5  mills  were  struck,  and  but  0.3  factory  chim- 
neys. Only  the  factories  had  fires  burning. 

A  mighty  work  has  been  wrought  by  glaciers  on  the  surface  of 
our  globe.  Long  before  this  fact  was  discovered  by  professional 
geologists  it  was  clear  to  many  of  the  plainer  people.  Jean  de 
Charpentier,  one  of  the  first  propounders  of  the  theory  of  glacial 


FOLK  OBSERVATION  295 

action  now  fundamental  in  geological  science,  relates :—  "When 
in  the  year  1815,  I  returned  from  the  magnificent  glaciers  of  the 
valley  of  the  Rhone,  I  spent  the  night  in  the  hamlet  of  Lourtier, 
in  the  cottage  of  Perraudin,  a  chamois-hunter.  Our  conversation 
turned  on  the  peculiarities  of  the  country,  and  especially  of  the 
glaciers  which  he  had  repeatedly  explored  and  knew  most  in- 
timately. 'Our  glaciers/  said  Perraudin,  'had  formerly  a  much 
larger  extent  than  now.  Our  whole  valley  was  occupied  by  a 
glacier  extending  as  far  as  Martigny,  as  is  proved  by  the  boulders 
in  the  vicinity  of  this  town,  and  which  are  far  too  large  for  the 
water  to  have  carried  them  thither/ '  Charpentier  adds  that  he 
afterward  met  with  similar  explanations  on  the  part  of  moun- 
taineers in  other  sections  of  Switzerland. 

Cowpox  was  long  observed  by  English  country  folk  to  be  a 
preventive  of  smallpox.  It  was  in  hearing  a  servant  woman  say 
so  that  Dr.  Jenner  was  drawn  to  the  study  which  ended  in  his 
successful  vaccinations,  in  all  the  triumphs  since  won  in  this  de- 
partment of  medical  science.  For  two  thousand  years  the  peasants 
of  Italy  have  suspected  mosquitoes  and  other  insects  to  be  con- 
cerned in  the  spread  of  malarial  and  other  fevers.  It  remained 
for  Dr.  Ronald  Ross  in  our  day  to  prove  that  the  suspicion  was 
founded  in  truth.  In  "The  Naturalist  in  La  Plata,"  one  of  the 
best  books  on  natural  history  ever  written,  Mr.  W.  H.  Hudson 
says :— "The  country  people  in  South  America  believe  that  the 
milky  secretion  exuded  by  the  toad  possesses  wonderful  curative 
properties;  it  is  their  invariable  specific  for  shingles— a  painful, 
dangerous  malady  common  amongst  them,  and  to  cure  it  living 
toads  are  applied  to  the  inflamed  part.  I  dare  say  learned  phy- 
sicians would  laugh  at  this  cure,  but  then,  if  I  mistake  not,  the 
learned  have  in  past  times  laughed  at  other  specifics  used  by  the 
vulgar,  but  which  now  have  honorable  places  in  the  pharmaco- 
poeia—pepsine,  for  example.  More  than  two  centuries  ago,  very 
ancient  times  for  South  America,  the  gauchos  were  accustomed 
to  take  the  lining  of  the  rhea's  (a  large  ostrich's)  stomach,  dried 
and  powdered,  for  ailments  caused  by  impaired  digestion ;  and  the 
remedy  is  popular  still.  Science  has  gone  over  to  them,  and  the 
ostrich-hunter  now  makes  a  double  profit,  one  from  the  feathers, 
and  the  other  from  the  dried  stomachs  which  he  supplies  to  the 


296  OBSERVATION 

chemists  of  Buenos  Ayres.  Yet  he  was  formerly  told  that  to  take 
the  stomach  of  the  ostrich  to  improve  his  digestion  was  as  wild 
an  idea  as  it  would  be  to  swallow  birds'  feathers  in  order  to  fly." 

Snake  poison  has  long  been  used  by  the  Hottentots  as  an  anti- 
dote to  snake  poison.  With  aid  from  the  Carnegie  Institution  of 
Washington,  Dr.  Hideyo  Noguchi,  of  the  University  of  Pennsyl- 
vania, has  succeeded  in  producing  antivenins,  to  use  the  medical 
term,  for  the  venoms  of  the  water-moccasin  and  Crotalus  adaman- 
ieus  snakes,  using  the  venoms  themselves  in  preparing  his  anti- 
dotes. He  is  continuing  his  researches  in  this  remarkable  field 
of  the  healing  art. 

Kelp,  as  it  drifts  and  sways  in  the  Atlantic,  attracts  from  the  sea 
both  the  iodine  and  the  bromine  dissolved  in  minute  quantities  in 
the  sea-water.  This  trait  of  fastening  upon  a  particular  and  rare 
element  is  displayed  by  plants  on  land  as  well  as  by  sea-weeds. 
In  the  Horn  silver  mine  of  Utah,  the  zinc  mingled  with  the  silver 
is  betokened  by  the  abundance  of  a  zinc  violet,  Viola  calaminaria, 
a  delicate  cousin  of  the  pansy.  In  Germany  this  little  flower  was 
believed  to  point  to  zinc  deposits  long  before  zinc  was  discovered 
in  its  juices.  The  late  Mr.  William  Dorn,  of  South  Carolina,  had 
faith  in  a  bush  of  unrecorded  name,  as  declaring  that  gold  veins 
stood  beneath  it :  that  his  faith  was  not  baseless  is  proved  by  the 
large  fortune  he  won  as  a  gold  miner  in  the  Blue  Ridge  country — 
his  guide  the  bush  aforesaid.  Mr.  Rossiter  W.  Raymond,  a 
famous  mining  engineer  of  New  York,  has  given  some  attention 
to  "indicative  plants"  of  this  kind.  He  is  of  opinion  that  their 
unwritten  lore  among  practical  miners,  prospectors,  hunters,  and 
Indians  is  well  worth  sifting. 

He  says : — "Judging  from  the  general  laws  of  the  distribution 
of  plants,  and  from  the  analogy  furnished  by  Viola  calaminaria, 
we  may  expect  that  an  indicative  plant  will  be,  not  a  distinct 
species,  but  a  variety  of  some  widely  distributed  species,  the  range 
of  the  species  as  a  whole  being  determined  by  general  conditions 
of  climate,  altitude  and  soil,  while  the  characteristics  of  the  variety 
are  affected  by  causes  peculiar  to  the  mineral  deposit.  Tempera- 
ture and  moisture,  as  Agricola  long  ago  pointed  out,  are  among 
these  causes,  and  color  is  one  of  the  most  sensitive  of  their  effects. 
It  is  quite  reasonable  to  believe  the  soil  may  affect  the  color  of  the 


A  BANK-SWALLOW  TEACHES        297 

plant  absorbing  it.  On  the  other  hand,  it  is  not  certain,  even  if  a 
plant  is  proved  to  indicate  by  color  or  other  peculiarities  the 
presence  of  silver,  that  silver  is  the  substance  actually  entering 
into  and  altering  the  plant.  The  effect  may  be  due  to  some  other 
mineral  substances  associated  with  the  silver-ores ;  and  our  silver- 
plant  may  be  indicative  of  silver  in  a  silver  region  only." 

Mr.  Raymond  remarks  that  a  general  relation  between  the  flora 
and  the  geological  formation  of  any  given  district  is  a  fact 
familiar  to  field-geologists.  Many  plants,  too,  indicate  the  neigh- 
borhood of  water.  A  botanist  knowing  the  root-length,  water- 
requirements  and  habits  of  different  species  can  often  determine 
from  the  surface  vegetation,  he  tells  us,  the  nature,  amount  and 
distance  of  the  underground  water-supply.1 

How  observation  may  lead  to  a  bold  and  successful  experiment 
is  told  by  Mr.  L.  E.  Chittenden,  Register  of  the  Treasury  under 
President   Lincoln,   in   his   Personal   Reminis- 
cences:- A  Lesson  from 

Between  the  Winooski  Valley  and  Lake  a  Bank-Swallow 
Champlain,  north  of  the  city  of  Burlington,  lies 
a  broad  sand  plain  high  above  the  lake  level,  through  which  the 
Central  Vermont  Railroad  was  to  be  carried  in  a  tunnel.  But  the 
sand  was  destitute  of  moisture  or  cohesiveness,  and  the  engineers, 
after  expending  a  large  sum  of  money,  decided  that  the  tunnel 
could  not  be  constructed  because  there  were  no  means  of  sustain- 
ing the  material  during  the  building  of  the  masonry.  The  removal 
of  so  large  a  quantity  of  material  from  a  cut  of  such  dimensions 
also  involved  an  expense  that  was  prohibitory.  The  route  was 
consequently  given  up  and  the  road  built  in  a  crooked  ravine 
through  the  centre  of  the  city,  involving  ascending  and  descending 
grades  of  more  than  130  feet  to  the  mile.  When  the  railroad  was 
opened  these  grades  were  found  to  involve  a  cost  which  practically 
drove  the  through  freights  to  a  competing  railroad. 

There  was  at  the  time  a  young  man  in  the  engineers'  office  of  the 

1In  his  paper  on  Indicative  Plants,"  published  in  the  Transactions  of 
the  American  Institute  of  Mining  Engineers,  1886,  Mr.  R.  W.  Raymond 
illustrated  in  natural  size  Viola  calaminaria,  Amorpha  crescens,  and  Erigo- 
nium  ovalifolium.  His  paper  is  followed  by  the  interesting  discussion  it 
called  forth. 


298  OBSERVATION 

railroad  who  said  that  he  could  tunnel  the  sand  bank  at  a  very 
small  cost.  He  was  summoned  before  the  managers  and  ques- 
tioned. "Yes,"  he  said,  "I  can  build  the  tunnel  for  so  many  dol- 
lars per  running  foot,  but  I  cannot  expect  you  to  act  upon  my 
opinion  when  so  many  American  and  European  engineers  have 
declared  the  project  impracticable."  The  managers  knew  that  the 
first  fifty  feet  of  the  tunnel  involved  all  the  difficulties.  They  of- 
fered him,  and  he  accepted,  a  contract  to  build  fifty  feet  of  the 
structure. 

His  plan  was  simplicity  itself.  On  a  vertical  face  of  the  bank 
he  marked  the  line  of  an  arch  larger  than  the  tunnel.  On  this 
line  he  drove  into  the  bank  sharpened  timbers,  twelve  feet  long, 
three  by  four  inches  square.  Then  he  removed  six  feet  of  the 
material  and  drove  in  another  arch,  just  inside  the  first  one,  of 
twelve-foot  timbers,  took  out  six  feet  more  of  sand,  and  repeated 
this  process  until  he  had  space  enough  to  commence  the  masonry. 
As  fast  as  this  was  completed  the  space  above  it  was  filled,  leaving 
the  timbers  in  place. 

Thus  he  progressed,  keeping  the  masonry  well  up  to  the  excava- 
tion, until  he  had  pierced  the  bank  with  the  cheapest  tunnel  ever 
constructed,  which  has  carried  the  traffic  of  a  great  railroad  for 
thirty  years,  and  now  stands  as  firm  as  on  its  completion. 

The  engineer  was  asked  if  there  was  any  suggestion  of  the 
structure  adopted  by  him  in  the  books  on  engineering.  "No,"  he 
said,  "it  came  to  me  in  this  way.  I  was  driving  by  the  place  where 
the  first  attempts  were  made,  of  which  a  colony  of  bank-swallows 
had  taken  possession.  It  occurred  to  me  that  these  little  engineers 
had  disproved  the  assertion  that  this  material  had  no  cohesion. 
They  have  their  homes  in  it,  where  they  raise  two  families  every 
summer.  Every  home  is  a  tunnel,  self -sustaining  without 
masonry.  A  larger  tunnel  can  be  constructed  by  simply  extending 
the  principle,  and  adopting  masonry.  This  is  the  whole  story. 
The  bank-swallow  is  the  inventor  of  this  form  of  tunnel  construc- 
tion. I  am  simply  a  copyist— his  imitator." 


CHAPTER  XXI 

EXPERIMENT 

Newton,  Watt,  Ericsson,  Rowland,  as  boys  were  constructive  .  .  .  The 
passion  for  making  new  things  .  .  .  Aid  from  imagination  and  trained 
dexterity  .  .  .  Edison  tells  how  he  invented  the  phonograph  .  .  .  Tele- 
phonic messages  record  themselves  on  a  steel  wire  .  .  .  Handwriting 
transmitted  by  electricity  .  .  .  How  machines  imitate  hands  .  .  .  Orig- 
inality in  attack. 

A  N  inventor  is  a  man  of  unusual  powers.    To  begin  with  he  is 
jLJL    cast  in  a  larger  mold  than  ordinary  men ;  he  has  keener  eyes, 
more  skilful  hands,  a  better  knitting  quality  of  brain.     In  his 
heart  he  believes  every  engine,  machine,  and  process  to  be  im- 
provable without  limit.    He  is  thoroughly  dis- 

Early  Talent  in  satisfied  with  things  as  they  are  and  alert  to 
Construction.  detect  where  an  old  method  can  be  bettered,  or 
a  gift  wholly  new  be  conferred  on  mankind,  as 
in  the  telephone  or  the  phonograph.  His  uncommon  faculty  of 
observation  we  have  had  occasion  to  remark.  Another  talent  as 
much  in  evidence,  and  quite  irrepressible  even  in  early  life,  impels 
him  to  make,  weave,  and  build.  Invariably  the  man  who  has  added 
to  the  resources  of  architecture,  engineering,  machine  design,  has 
begun  as  a  boy  in  repeating  the  rabbit-hutches,  windmills,  and 
whittled  sailing  craft  of  bigger  boys.  This  means  that  he  soon 
acquires  a  mastery  of  chisel,  plane,  and  drill,  that  the  lathe  be- 
comes as  obedient  to  him  as  his  own  hand.  Watt,  Maudslay, 
Stephenson,  and  every  peer  they  ever  had,  could  go  to  the  bench 
and  make  a  valve,  a  mitre-wheel,  a  link-motion  just  as  imaged  in 
their  mind's  eye.  Lacking  this  dexterity  other  men,  occasionally 
fertile  in  good  ideas,  never  bring  them  to  the  birth. 

While  inventors  owe  their  talents  to  nature,  these  talents  need 
sound  training,  if  at  a  master's  hands,  so  much  the  better.  Just 
as  the  best  place  to  learn  how  to  paint,  is  the  studio  of  a  great 


300  EXPERIMENT 

artist,  so  the  best  school  for  ingenuity  is  the  workshop  of  a  great 
inventor.  Maudslay,  who  devised  the  slide-rest  for  lathes,  and 
Clement,  who  designed  the  first  rotary  planer,  were  trained  by 
Bramah,  who  invented  the  famous  hydraulic  press,  and  locks  of 
radically  new  and  excellent  pattern.  Whitworth,  who  created 
lathes  of  new  refinement,  who  established  new  and  exact  stand- 
ards of  measurement  in  manufacturing,  was  trained  by  Maudslay ; 
so  was  Nasmyth,  who  devised  the  steam  hammer.  Mr.  Edison 
in  his  laboratory  and  workshop  has  called  forth  the  ingenuity  of 
many  an  assistant  who  has  since  won  fame  and  fortune  by  inde- 
pendent work. 

But  as  a  rule  inventors,  like  the  vast  brotherhood  of  other  men, 
must  toil  by  themselves,  and  get  what  good  they  can  out  of  un- 
aided diligence.  Cobbett  used  to  say  that  he  thought  with  the 
point  of  his  pen ;  the  very  act  of  writing  lifted  into  consciousness 
many  an  idea  which  otherwise  had  died  stillborn.  Beethoven, 
like  all  other  great  tone-poets,  would  play  a  few  bars  as  they  came 
to  his  imagination,  and  while  he  touched  the  keys  the  music,  as  if 
with  pinions  of  its  own,  took  such  heavenly  flights  as  those  of 
the  Fifth  Symphony.  In  just  this  mode  while  an  inventor  is  shap- 
ing a  new  model  he  feels  how  he  can  better  its  lines,  give  it  a 
simpler  design  than  he  first  intended.  His  hands  and  eyes  think 
as  well  as  his  brain ;  while  lever,  link,  and  cam  unite  together  they 
suggest  how  they  may  be  more  compactly  built,  more  effectively 
joined.  His  partner,  the  discoverer,  is  under  the  same  spell  with 
regard  to  some  long-standing  puzzle  of  rock,  or  plant,  or  star.  Be- 
cause in  his  soul  he  believes  nature  to  be  intelligible  to  her  very 
core,  he  is  sure  that  this  particular  puzzle  can  be  fathomed,  and 
he  keeps  thinking  day  -by  day  of  possible  solutions.  At  other 
times,  and  even  during  sleep,  his  brain  is  subconsciously  at  work 
upon  his  problem,  bringing  to  view  promising  points  for  attack. 
With  new  light  he  is  bold  enough  to  say,  this  problem  can  be 
solved  by  me.  At  last  dawns  the  happy  morning  when  he  verifies 
a  shrewd  guess,  or  when  a  crucial  experiment  stamps  a  theory  as 
proven  truth,  indispensable  aid  having  arisen  as  one  attempt, 
through  baffling  failure,  suggested  the  next.  All  boys  and  girls 
are  the  better,  happier,  more  useful  when  they  are  early  and 
thoroughly  trained  to  use  their  eyes,  ears,  and  hands;  to  the  in- 


NEWTON  IN  BOYHOOD  301 

ventor  and  discoverer  this  training  opens  a  career  which  other- 
wise is  denied. 

Among  the  greatest  of  the  sons  of  men  who  have  united  the 
faculties  of  invention  and  discovery  stands  Sir  Isaac  Newton.  As 
with  his  compeers  we  find  that  his  art  as  an  inventor  was  but  the 
flower  of  his  handicraft  as  a  mechanic. 

Sir  Isaac  Newton  almost  from  the  cradle  was  a  builder.  His 
biographer,  Sir  David  Brewster,  says  :— 

"He  had  not  been  long  at  school  before  he 
exhibited  a  taste  for  mechanical  inventions.  Newton  as  a 
With  the  aid  of  little  saws,  hammers,  hatchets, 
and  tools  of  all  sorts,  he  was  constantly  occu- 
pied during  his  play  hours  in  the  construction  of  models  of  known 
machines,  and  amusing  contrivances.  The  most  important  pieces 
of  mechanism  which  he  thus  constructed,  were  a  windmill,  a 
water-clock,  and  a  carriage  to  be  moved  by  the  person  who  sat  in 
it.  When  a  windmill  was  in  course  of  being  erected  near  Grant- 
ham,  Sir  Isaac  frequently  watched  the  operations  of  the  workmen, 
and  acquired  such  a  thorough  knowledge  of  its  mechanism,  that 
he  completed  a  working  model  of  it,  which  Dr.  Stukely  says  was 
as  clean  and  curious  a  piece  of  workmanship  as  the  original.  This 
model  was  frequently  placed  on  the  top  of  the  house  in  which  he 
lived  at  Grantham,  and  was  put  in  motion  by  the  action  of  the 
wind  upon  its  sails.  In  calm  weather,  however,  another  mechan- 
ical agent  was  required,  and  for  this  purpose  a  mouse  was  put 
in  requisition,  which  went  by  the  name  of  miller. 

"The  water-clock  constructed  by  Sir  Isaac  was  a  more  useful 
piece  of  mechanism  than  his  windmill.  It  was  made  out  of  a  box 
which  he  begged  from  Mrs.  Clark's  brother,  and,  according  to 
Dr.  Stukely,  to  whom  it  was  described  by  those  who  had  seen  it, 
it  resembled  pretty  much  our  common  clocks  and  clock-cases,  but 
was  less  in  size,  being  about  four  feet  in  height,  and  of  a  pro- 
portional breadth.  There  was  a  dial-plate  at  top  with  figures  of 
the  hours.  The  index  was  turned  by  a  piece  of  wood,  which  either 
fell  or  rose  by  water  dropping. 

"The  mechanical  carriage  which  Sir  Isaac  is  said  to  have  in- 
vented, was  a  four-wheeled  vehicle,  and  was  moved  with  a  handle 
or  winch  wrought  by  the  person  who  sat  in  it.  We  can  find  no 


302  EXPERIMENT 

distinct  information  respecting  its  construction  or  use,  but  it 
must  have  resembled  a  Merlin's  chair,  which  is  fitted  to  move 
only  on  the  smooth  surface  of  a  floor,  and  not  overcome  the  in- 
equalities of  a  common  road. 

"He  introduced  the  flying  of  paper  kites,  and  is  said  to  have  in- 
vestigated their  best  forms  and  proportions,  as  well  as  the  number 
and  position  of  the  points  to  which  the  string  should  be  attached. 
He  constructed  also  lanterns  of  crimpled  paper,  in  which  he  placed 
a  candle  to  light  him  to  school  in  the  dark  winter  mornings ;  and 
in  the  dark  nights  he  tied  them  to  the  tails  of  his  kites,  in  order  to 
terrify  the  country  people,  who  took  them  for  comets. 

"In  the  yard  of  the  house  where  he  lived,  he  was  frequently 
observed  to  watch  the  motion  of  the  sun.  He  drove  wooden  pegs 
into  the  walls  and  roofs  of  the  buildings,  as  gnomons  to  mark 
by  their  shadows  the  hours  and  half-hours  of  the  day.  It  does 
not  appear  that  he  knew  how  to  adjust  these  lines  to  the  latitude 
of  Grantham ;  but  he  is  said  to  have  succeeded,  after  some  years' 
observation,  in  making  them  so  exact  that  anybodv  could  tell  what 
o'clock  it  was  by  Isaac's  dial,  as  it  was  called. 

"Sir  Isaac  himself  told  Mr.  Conduit  that  one  of  the  earliest 
scientific  experiments  which  he  made  was  in  1658,  on  the  day  of 
the  great  storm  when  Cromwell  died,  and  when  he  himself  had 
just  entered  into  his  sixteenth  year.  In  order  to  determine  the 
force  of  the  gale  he  jumped  first  in  the  direction  in  which  the 
wind  blew,  and  then  in  opposition  to  the  wind;  and  after  meas- 
uring the  length  of  the  leap  in  both  directions,  and  comparing  it 
with  the  length  to  which  he  could  jump  on  a  perfectly  calm  day, 
he  was  enabled  to  compute  the  force  of  the  storm.  Sir  Isaac 
added,  that  when  his  companions  seemed  surprised  at  his  saying 
that  any  particular  wind  was  a  foot  stronger  than  any  he  had 
known  before,  he  carried  them  to  the  place  where  he  had  made  the 
experiment,  and  showed  them  the  measure  and  marks  of  his 
several  leaps. 

"When  a  young  man  he  made  a  telescope  with  his  own  hands." 

James  Watt,  who  became  the  chief  improver  of  the  steam  en- 
gine, when  a  boy  received  from  his  father  a  set  of  small  carpentry 
tools.  The  little  fellow  would  take  his  toys  to  pieces,  rebuild  them 
and  invent  playthings  wholly  new.  A  cousin  of  his,  Mrs.  Camp- 


ERICSSON'S  PRECOCITY  303 

bell,  has  recorded  that  Watt  as  a  lad  was  often  blamed  for  idle- 
ness ;  she  adds  :— 

"His  active  mind  was  employed  in  investigating  the  properties 
of  steam ;  he  was  then  fifteen,  and  once  in  con- 
versation  he   informed   me  that  he   had   read         Watt  as  an 
twice,    with    great    attention,    S'Gravesande's       Inquiring  Boy. 
'Elements  of  Natural  Philosophy/  adding  that 
it  was  the  first  book  upon  that  subject  put  into  his  hands,  and  that 
he  still  thought  it  one  of  the  best.  While  under  his  father's  roof, 
he  went  on  with  various  chemical  experiments,  repeating  them 
again  and  again  until  satisfied  of  their  accuracy  from  his  own  ob- 
servations.   He  had  made  for  himself  a  small  electrical  machine, 
and  sometimes  startled  his  young  friends  by  giving  them  sudden 
shocks  from  it." 

John  Ericsson  as  a  child  was  the  wonder  of  the  neighborhood, 
says  his  biographer,  Mr.  William  C.  Conant.    From  the  first  he 
exhibited   the   qualities   distinguishing  him   in 
later  life.    His  industry  was  ceaseless;  he  was        Astonishing 

.  .  .  Precocity  of 

busy  from  morning  to  night  drawing,  planning  Ericsson. 

and  constructing.  The  machinery  at  the  mines 
near  his  home  was  to  him  an  endless  source  of  wonder  and  delight. 
In  the  early  morning  he  hastened  to  the  works,  carrying  with 
him  a  drawing  pencil,  bits  of  paper,  pieces  of  wood,  and  a  few 
rude  tools.  There  he  would  remain  the  day  through,  seeking  to 
discover  the  principles  of  motion  in  the  machines,  and  striving  to 
copy  their  forms.  In  his  tenth  year  this  boy  undertook  to  design 
a  pump  for  draining  the  mines  of  water.  The  motor  was  to  be  a 
windmill.  Such  a  contrivance  the  young  inventor  had  never 
seen,  yet  he  succeeded  in  drawing  designs  for  his  mill  after  the 
most  approved  fashion  of  skilled  engineers  by  following  a  verbal 
description  given  by  his  father  of  a  mill  he  had  just  visited. 

Henry  A.  Rowland  became  at  Johns  Hopkins  University  in 
Baltimore  one  of  the  great  physical  investigators  and  inventors 
of  the  nineteenth  century.     As  a  boy  he  de- 
lighted   in    chemical    experiments,    glass-blow-    Rowland's  Early 
ing,  and  similar  occupations.    The  family  were       Experiments, 
often   summoned  by  the  young  enthusiast  to 
listen  to  lectures  which  were  fully  illustrated  by  experiments,  not 


304  EXPERIMENT 

always  free  from  prospective  danger.  His  first  five-dollar  bill 
bought  him,  to  his  delight,  a  galvanic  battery.  The  sheets  of  the 
New  York  "Observer"  he  converted  into  a  hot-air  balloon,  which 
made  a  brilliant  ascent  and  flight,  setting  fire,  at  last,  to  the  roof 
of  a  neighboring  house.  One  day  he  saw  a  pump  at  work  in  the 
hold  of  a  steamer,  sending  out  a  stream  which  fell  from  a  height 
of  five  or  six  feet  to  the  river.  "Why,"  he  exclaimed,  "don't  you 
put  that  pipe  down  into  the  river  and  save  power  ?"  As  a  student 
at  the  Troy  Polytechnical  Institute  he  invented  a  method  of 
winding  naked  strips  of  wire  on  cloth  so  as  virtually  to  effect  its 
insulation.  This  was  afterward  profitably  patented  by  some  one 
else. 

In  "The  Senses  and  the  Intellect"  Professor  Alexander  Bain 
considers  the  inventing  and  discovering  mind  :— 

"Not  one  of  the  leading  mental  peculiarities 
The  Passion  for      applicable  to  scientific  constructiveness   can  be 

Experiment.  dispensed  with  in  the  constructions  of  prac- 
tice :— the  intellectual  store  of  ideas  applicable 
to  the  special  department ;  the  powerful  action  of  the  associating 
forces ;  a  very  clear  perception  of  the  end,  in  other  words,  sound 
judgment;  and,  lastly,  that  patient  thought,  which  is  properly 
an  entranced  devotion  of  the  energies  to  the  subject  in  hand, 
rendering  application  to  it  spontaneous  and  easy. 

"With  reference  to  originality  in  all  departments,  whether 
science,  practice,  or  fine  art,  there  is  a  point  of  character  that  de- 
serves notice,  as  being  more  obviously  of  value  in  practical  in- 
ventions and  in  the  conduct  of  business  and  affairs— I  mean  an 
active  turn,  or  a  profuseness  of  energy,  put  forth  in  trials  of  all 
kinds  on  the  chance  of  making  lucky  hits.  In  science,  meditation 
and  speculation  can  do  much,  but  in  practice,  a  disposition  to  try 
experiments  is  of  the  utmost  service.  Nothing  less  than  a  fanati- 
cism of  experimentation  could  have  given  birth  to  some  of  our 
grandest  practical  combinations.  The  great  discovery  of  Da- 
guerre,  for  example,  could  not  have  been  regularly  worked  out 
by  any  systematic  and  orderly  research ;  there  was  no  way  but  to 
stumble  upon  it,  so  unlikely  and  remote  were  the  actions  brought 
together  in  one  consecutive  process.  The  discovery  is  unaccount- 
able, until  we  learn  that  the  author  had  been  devoting  himself 


DAGUERRE'S  DISCOVERY  305 

to  experiments  for  improving  the  diorama,  and  thereby  got 
deeply  involved  in  trials  and  operations  far  removed  from  the 
beaten  paths  of  inquiry.  The  energy  that  prompts  to  endless 
attempts  was  found  in  a  surprising  degree  in  Kepler.  A  similar 
untiring  energy— the  union  of  an  active  temperament  with  intense 
fascination  for  his  subject— appears  in  the  character  of  Sir  Wil- 
liam Herschel.  When  these  two  attributes  are  conjoined;  when 
profuse  active  vigor  operates  on  a  field  that  has  an  unceasing 
charm  for  the  mind,  we  then  see  human  nature  surpassing  itself. 

"The  invention  of  photography  by  Daguerre  illustrates  the 
probable  method  whereby  some  of  the  most  ancient  inventions 
were  arrived  at.  The  inventions  of  the  scarlet  dye,  of  glass,  of 
soap,  of  gunpowder,  could  have  come  only  by  accident ;  but  the 
accident,  in  most  of  them,  would  probably  fall  into  the  hands  of 
men  engaged  in  numerous  trials  upon  the  materials  involved.  In- 
tense application — 'days  of  watching,  nights  of  waking'— went 
with  ancient  discoveries,  as  well  as  with  modern.  In  the  historical 
instances,  we  know  as  much.  The  mental  absorption  of  Archi- 
medes is  a  proverb. 

"The  wonderful  part  of  Daguerre's  discovery  consists  in  the 
succession  of  processes  that  had  to  concur  in  one  operation  be- 
fore any  effect  could  arise.  Having  taken  a  silver  plate,  iodine 
is  first  used  to  coat  the  surface;  the  surface  is  then  exposed  to 
the  light,  but  the  effect  produced  is  not  apparent  till  the  plate 
has  been  immersed  in  the  vapor  of  mercury.  To  fall  upon  such 
a  combination,  without  any  clue  derived  from  previous  knowl- 
edge, an  innumerable  series  of  fruitless  trials  must  have  been 
gone  through. 

"A  remark  may  be  made  here,  applicable  alike  to  science  and 
to  practice.  Originality  in  either  takes  two  forms— observation 
or  experiment  on  the  one  hand,  and  the  identifying  processes  of 
abstraction,  induction,  and  deduction  on  the  other.  In  the  first, 
the  bodily  activities  and  the  senses  are  requisite;  the  last  are  the 
purely  intellectual  forces.  It  is  not  by  high  intellectual  force  that 
a  man  discovers  new  countries,  new  plants,  new  properties  of  ob- 
jects ;  it  is  by  putting  forth  an  unusual  force  of  activity,  adven- 
ture, inquisitorial  and  persevering  search.  All  this  is  necessary 
in  order  to  obtain  the  observations  and  facts  in  the  first  instance ; 


306  EXPERIMENT 

when  these  are  collected  in  sufficient  number,  a  different  aptitude 
is  brought  to  bear.  By  identifying  and  assimilating  the  scattered 
materials,  general  properties  and  general  truths  are  obtained,  and 
these  may  be  pushed  deductively  into  new  applications;  in  all 
which  a  powerful  reach  of  similarity  is  the  first  requisite ;  and 
this  may  be  owned  by  men  totally  destitute  of  the  active  qualities 
necessary  for  observation  and  experiment." 

In  "The  Hazard  of  New  Fortunes"  Mr.  W.  D.  Howells  depicts 
a  man  of  force  who,  without  education,  becomes  rich.  He  has 
little  patience  with  poor  men,  who,  he  says, 
The  Chief  "don't  get  what  they  want  because  they  don't 

want  it  bad  enough."  The  rough  old 
Westerner,  Dryfoos,  was  sound  in  his  view. 
Success  in  discovery  as  in  money-making  is  as  much  a  matter  of 
passion  as  of  intelligence,  says  Mr.  O.  F.  Cook  :— 

"The  first  and  most  essential  preliminary  for  a  successful  in- 
vestigation is  an  interest  in  the  question,  and  any  method  which 
tends  to  diminish  or  relax  interest  is  false  and  futile.  Diligence 
in  learning  the  facts  of  a  science  is  a  distinctly  unfavorable  symp- 
tom in  a  would-be  investigator  when  unaccompanied  by  a  vital 
constructive  interest.  That  a  student  hoards  facts  does  not  mean 
that  he  will  build  anything  with  them.  Intellectual  misers  are 
common,  and  are  quite  as  unprofitable  as  the  monetary  variety. 
A  scientific  specialist  may  have  vast  knowledge  and  life-long  ex- 
perience, and  yet  may  never  entertain  an  original  idea  or  make 
a  new  rift  in  the  wall  of  the  unknown  which  bafBed  his  predeces- 
sors. Indeed,  such  men  commonly  resent  a  readjustment  of  the 
bounds  of  knowledge  as  an  interference  with  their  vested  capital 
of  erudition. 

"Investigation  is  a  sentiment,  an  instinct,  a  habit  of  mind;  it 
is  man's  effort  at  knowing  and  enjoying  the  universe.  The  pro- 
ductive investigator  desires  knowledge  for  a  purpose ;  he  may  not 
be  eager  for  knowledge  in  general,  nor  for  new  knowledge  in 
particular.  He  values  details  for  their  bearing  on  the  problem 
he  hopes  to  solve.  He  can  gather  and  sift  them  to  advantage  only 
in  the  light  of  a  radiant  interest,  and  his  ability  to  utilize  them 
for  correct  information  depends  on  the  delicacy  of  his  perception 
and  the  strength  of  his  mental  grasp.  The  investigator,  like  the 


PICTURING  FACULTY  30? 

athlete,  must  first  be  born ;  he  can  not  be  made  to  order,  but  his 
training  determines  the  degree  of  excellence  to  which  he  can 
attain.  No  amount  of  training  can  remove  organic  defects,  but 
bad  training  may  be  worse  than  none  in  lessening  the  attainment 
of  the  most  capable.  That  education  is  false  and  injurious  which 
puts  the  matter  first  and  retards  or  prevents  the  development  of 
constructive  mental  ability,  a  power  not  peculiar  to  the  investiga- 
tor, but  in  him  reaching  the  greatest  scope  and  freedom  of 
action." 

A  picturing  faculty  such  as  comes  to  the  flower  in  an  inventor 
may  often  be  observed  in  a  skilful  workman.     In  a  shoe  factory 
a  veteran  will  lift  a  hide,  utterly  irregular  in 
form,  and  cut  soles  and  heels  from  it,  so  that          Aid  from 
the  remaining  scraps  are  a  mere  trifle,  while     Picturing  Power. 
flaws  have  been  avoided. 

Hugh  Miller,  in  "My  Schools  and  Schoolmasters,"  thus  speaks 
of  a  fellow  stone-mason :— "John  Fraser's  strength  had  never 
been  above  the  average  of  that  of  Scotchmen,  and  it  was  now 
considerably  reduced;  nor  did  his  mallet  deal  more  or  heavier 
blows  than  that  of  the  common  workman.  He  had,  however,  an 
extraordinary  power  of  conceiving  of  the  finished  piece  of  work, 
as  lying  within  the  rude  stone  from  which  it  was  his  business  to 
disinter  it ;  and  while  ordinary  stone-cutters  had  to  repeat  and  re- 
repeat  their  lines  and  draughts,  and  had  in  this  way  virtually  to 
give  their  work  several  surfaces  in  detail  ere  they  reached  the 
true  one,  old  John  cut  upon  the  true  figure  at  once,  and  made  one 
surface  serve  for  all.  In  building,  too,  he  exercised  a  similar 
power;  he  hammer-dressed  his  stones  with  fewer  strpkes  than 
other  workmen,  and  in  fitting  the  interspaces  between  the  stones 
already  laid,  always  picked  from  out  the  heap  at  his  feet  the  stone 
that  exactly  filled  the  place ;  while  other  operatives  busied  them- 
selves in  picking  up  stones  that  were  too  small  or  too  large ;  or, 
if  they  set  themselves  to  reduce  the  too  large  ones,  reduced  them 
too  little  or  too  much,  and  had  to  fit  and  fit  again.  Whether  build- 
ing or  hewing,  John  never  seemed  in  a  hurry.  He  has  been  seen, 
when  far  advanced  in  life,  working  very  leisurely,  as  became  his 
years,  on  one  side  of  a  wall,  and  two  stout  young  fellows  building 
against  him  on  the  other  side— toiling,  apparently,  twice  harder 


308  EXPERIMENT 

than  he,  but  the  old  man  always  contriving  to  keep  a  little  ahead 
of  them  both." 

Henry  Maudslay,  famous  as  an  inventor,  had  the  same  ex- 
quisite sense  of  form.  When  he  executed  a  piece  of  work  he 
was  greatly  indebted  to  the  dexterity  he  had  acquired  as  a  black- 
smith in  early  life.  He  used  to  say  that  to  be  a  good  smith  you 
must  be  able  to  see  in  an  iron  bar  the  object  you  mean  to  get  out 
of  it  with  hammer  and  chisel,  just  as  the  sculptor  sees  the  statue 
he  intends  to  carve  from  a  block  of  marble. 

Inventors  and  artists  have  in  common  a  keen  perception  of 

form,  an  ability  to  confer  form  with  skill  and  accuracy.     Often 

the  same  man  is  at  once  inventor  and  artist. 

Eyes  and  Hands      Of  this  class  Leonardo  da  Vinci  is  the  most 

Inform  the  Brain,     illustrious  example.     Alexander  Nasmyth,   of 

Edinburgh,     who     invented     the     bow-string 

bridge,  was  an  eminent  painter  of  portraits  and  landscapes.     His 

son,  James  Nasmyth,  who  devised  the  steam  hammer  and  the 

steam  pile-driver,  tells  us  in  his  autobiography : — 

"My  father  taught  me  to  sketch  with  exactness  every  object, 
whether  natural  or  artificial,  so  as  to  enable  the  hand  accurately 
to  reproduce  what  the  eye  had  seen.  In  order  to  acquire  this  al- 
most invaluable  art,  he  was  careful  to  educate  my  eye,  so  that  I 
might  perceive  the  relative  proportions  of  objects  placed  before 
me.  He  would  throw  down  at  random  a  number  of  bricks,  or 
pieces  of  wood  representing  them,  and  set  me  to  copy  their  forms, 
proportions,  lights  and  shadows.  I  have  often  heard  him  say  that 
any  one  who  could  make  a  correct  drawing  in  regard  to  outline, 
and  also  indicate  by  a  few  effective  touches  the  variation  of  lights 
and  shadows  of  such  a  group  of  model  objects,  might  not  despair 
of  making  a  good  and  correct  sketch  of  York  Minster.  My 
father  was  an  enthusiast  in  praise  of  this  graphic  language,  and 
I  have  followed  his  example.  In  fact  it  formed  a  principal  part 
of  my  own  education.  It  gave  me  the  power  of  recording  obser- 
vations with  a  few  graphic  strokes  of  the  pencil,  and  far  sur- 
passing in  expression  any  number  of  mere  words.  This  graphic 
eloquence  is  one  of  the  highest  gifts  in  conveying  clear  and  cor- 
rect ideas  as  to  the  forms  of  objects— whether  they  be  those  of 
a  simple  and  familiar  kind,  or  of  some  form  of  mechanical  con- 


TRAINING  THE  WHOLE  BOY        309 

struction,  or  of  the  details  01  a  fine  building,  or  the  characteristic 
features  of  a  wide-stretching  landscape.  This  accomplishment 
of  accurate  drawing,  which  I  achieved  for  the  most  part  in  my 
father's  workroom,  served  me  many  a  good  turn  in  future  years 
with  reference  to  the  engineering  work  which  became  the  busi- 
ness of  my  life." 

His  mastery  of  the  pencil  had  undoubtedly  a  great  deal  to  do  in 
cultivating  his  powers  of  inventive  imagination.  He  says :—  "It 
is  one  of  the  most  delightful  results  of  the  possession  of  the  con- 
structive faculty,  that  one  can  build  up  in  the  mind  mechanical 
structures  and  set  them  to  work  in  imagination,  and  observe  be- 
forehand the  various  details  performing  their  respective  func- 
tions, as  if  they  were  in  absolute  form  and  action.  Unless  this 
happy  faculty  exists  in  the  brain  of  the  mechanical  engineer,  he 
will  have  a  hard  and  disappointing  life  before  him.  It  is  the 
early  cultivation  of  the  imagination  which  gives  the  right  flexibil- 
ity to  the  thinking  faculty." 

Drawing  is  one  of  the  courses  in  every  manual  training  school 
in  America.  The  first  of  these  schools  was  organized  in  1879  a* 
St.  Louis,  under  the  direction  of  Professor  C. 
M.  Woodward.  Within  the  past  thirty  years,  Manual  Training, 
from  the  kindergarten  to  the  university,  Amer- 
ican education  has  addressed  itself  as  never  before  to  bringing 
out  all  the  talents  of  pupils  and  students.  In  earlier  days  there 
was  little  appeal  to  sense  perception,  to  dexterity,  to  the  faculties 
of  eye  and  hand  which  all  too  soon  pass  out  of  plasticity,  to  leave 
the  young  man  or  woman  for  life  destitute  of  powers  which, 
had  they  been  duly  elicited,  would  have  broadened  their  careers 
by  widening  their  horizons.  To-day,  happily,  our  schools  are  more 
and  more  supplementing  literary  and  mathematical  courses  with 
instruction  in  the  use  of  tools,  in  modeling,  design,  and  pattern- 
making.  Every  process  is  thoroughly  explained.  All  the  studies 
are  linked  into  series ;  these  unite  practice  and  its  reasons  with  a 
thoroughness  impossible  in  the  outworn  schemes  of  apprentice- 
ship. 

All  this  is  a  distinct  aid  to  inventiveness.  As  Professor  Wood- 
ward says  in  "Manual  Training  in  Education" : — "Manual  train- 
ing cultivates  a  capacity  for  executive  work,  a  certain  power  of 


310  EXPERIMENT 

creation.  Every  manual  exercise  involves  the  execution  of  a 
clearly  defined  plan.  Familiar  steps  and  processes  are  to  be  com- 
bined with  new  ones  in  a  rational  order  and  for  a  definite  purpose. 
As  a  rule  these  exercises  are  carefully  chosen  by  the  instructor. 
At  proper  times  and  in  reasonable  degree,  pupils  are  set  to  form- 
ing and  executing  their  own  plans.  Here  is  developed  not  a  single 
faculty,  but  a  combination  of  many  faculties.  Memory,  com- 
parison, imagination,  and  a  train  of  reasoning,  all  are  necessary 
in  creating  something  new  out  of  the  old." 

Every  inventor  of  mark  is  a  man  of  native  dexterity  whose 
skill  has  been  thoroughly  cultivated.  Let  us  observe  such  a  man 
as  he  came  to  an  extraordinary  triumph.  One 
How  the  of  the  great  inventions  of  all  time  is  the 

jnograp  phonograph,  giving  us  as  it  does  accurate  re- 

cords of  sound  which  may  be  repeated  as  often 
as  we  please.  The  ideas  which  issued  in  the  perfected  instrument 
were  for  years  germinating  in  Mr.  Edison's  mind ;  they  took  their 
rise  in  his  recording  telegraph.  One  afternoon  Mr.  Edison  told 
the  story  to  the  late  Mr.  George  Parsons  Lathrop,  who  published 
it  in  Harpers'  Magazine  for  February,  1890:— "I  worked  a  circuit 
in  the  daytime  at  Indianapolis,  and  got  a  small  salary  for  doing 
it.  But  at  night  with  another  operator  named  Parmley,  I  used 
to  receive  newspaper  reports  just  for  the  practice.  The  regular 
operator,  who  was  given  to  copious  libations,  was  glad  enough  to 
sleep  off  the  effects  while  we  did  his  work  for  him  as  well  as  we 
could.  I  would  sit  down  for  ten  minutes,  and  take  as  much  as  I 
could  from  the  instrument,  carrying  the  rest  in  my  memory. 
Then,  while  I  wrote  out,  Parmley  would  serve  his  turn  at  taking ; 
and  so  on.  This  worked  well  until  they  put  a  new  man  on  at  the 
Cincinnati  end.  He  was  one  of  the  quickest  despatchers  in  the 
business,  and  we  soon  found  it  was  hopeless  for  us  to  try  to  keep 
up  with  him.  Then  it  was  that  I  worked  out  my  first  invention, 
and  necessity  was  certainly  the  mother  of  it. 

"I  got  two  old  Morse  registers,  and  arranged  them  in  such  a 
way  that  by  running  a  strip  of  paper  through  them,  the  dots  and 
dashes  were  recorded  on  it  by  the  first  instrument  as  fast  as  they 
were  delivered  from  the  Cincinnati  end,  and  were  transmitted  to 
us  through  the  other  instrument  at  any  desired  rate  of  speed  or 


BIRTH  OF  THE  PHONOGRAPH      311 

slowness.  They  would  come  in  on  one  instrument  at  the  rate  of 
forty  words  a  minute,  and  we  would  grind  them  out  of  the  other 
at  the  rate  of  twenty-five.  Then  were  n't  we  proud!  Our  copy 
used  to  be  so  clean  and  beautiful  that  we  hung  it  up  on  exhibition ; 
and  our  manager  used  to  come  and  gaze  at  it  silently,  with  a 
puzzled  expression.  Then  he  would  depart,  shaking  his  head  in  a 
troubled  sort  of  way.  He  could  not  understand  it ;  neither  could 
any  of  the  other  operators ;  for  we  used  to  drag  off  my  impromptu 
automatic  recorder  and  hide  it  when  our  toil  was  over.  But  the 
crash  came  when  there  was  a  big  night's  work— a  presidential 
vote,  I  think  it  was — and  copy  kept  pouring  in  at  the  top  rate 
of  speed,  until  we  fell  an  hour  and  a  half  or  two  hours  behind. 
The  newspapers  sent  in  frantic  complaints,  an  investigation  was 
made,  and  our  little  scheme  was  discovered.  We  could  n't  use 
it  any  more. 

"It  was  that  same  rude  automatic  recorder,"  Edison  explained, 
"that  indirectly— yet  not  by  accident,  but  by  logical  deduction— 
led  me  long  afterward  to  invent  the  phonograph.  I  '11  tell  you 
how  this  came  about.  After  thinking  over  the  matter  a  great 
deal,  I  came  to  the  point  where,  in  1877,  I  had  worked  out  satis- 
factorily an  instrument  which  would  not  only  record  telegrams 
by  indenting  a  strip  of  paper  with  dots  and  dashes  of  the  Morse 
code,  but  would  also  repeat  a  message  any  number  of  times  at 
any  rate  of  speed  required.  I  was  then  experimenting  with  the 
telephone  also,  and  my  mind  was  filled  with  theories  of  sound 
vibrations  and  their  transmission  by  diaphragms.  Naturally 
enough,  the  idea  occurred  to  me:  If  the  indentations  on  paper 
could  be  made  to  give  forth  again  the  click  of  the  instrument,  why 
could  not  the  vibrations  of  a  diaphragm  be  recorded  and  similarly 
reproduced  ?  I  rigged  up  an  instrument  hastily,  and  pulled  a  strip 
of  paper  through  it,  at  the  same  time  shouting,  'Hallo !'  Then  the 
paper  was  pulled  through  again,  my  friend  Batchelor  and  I  listen- 
ing breathlessly.  We  heard  a  distinct  sound,  which  a  strong 
imagination  might  have  translated  into  the  original  'Hallo !'  That 
was  enough  to  lead  me  to  a  further  experiment.  But  Batchelor 
was  sceptical,  and  bet  me  a  barrel  of  apples  that  I  could  n't  make 
the  thing  go.  I  made  a  drawing  of  a  model,  and  took  it  to  Mr. 
Kruesi,  at  that  time  engaged  on  piece-work  for  me.  I  marked  it 


312  EXPERIMENT 

$4,  and  told  him  it  was  a  talking  machine.  He  grinned,  thinking 
it  a  joke;  but  set  to  work,  and  soon  had  the  model  ready.  I  ar- 
ranged some  tin-foil  on  it,  and  spoke  into  the  machine.  Kruesi 
looked  on,  and  was  still  grinning.  But  when  I  arranged  the 
machine  for  transmission,  and  we  both  heard  a  distinct  sound 
from  it,  he  nearly  fell  down  in  his  fright;  I  was  a  little  scared 
myself,  I  must  admit.  I  won  that  barrel  of  apples  from  Batchelor, 
though,  and  was  mighty  glad  to  get  it." 

In  October,  1905,  I  paid  Mr.  Edison  a  visit  at  his  laboratory, 

when  he  showed  me  the  phonograph  as  now  perfected.     Chief 

among  his  improvements  is  a  composition  for 

The  Latest          records  which  is  much  harder  than  the  wax 

formerly  employed,  and  may  therefore  revolve 

more  swiftly  with  no  fear  of  blurring.     His  reproducer  is  to-day 

a  built-up  diaphragm  of  mica,  highly  sensitive.    In  the  reproducer 


Edison  phonograph. 

A,  speaking  tube.  B,  D,  scale.  C,  receiving 
cylinder.  E,  repeat  lever.  F,  swivel  plate.  G, 
connecting  key.  H,  foot  trip.  I,  plug  attach- 
ment. J,  ear-tubes.  K,  switch. 

arm  is  placed  the  highly  polished,  button-shaped  sapphire  which 
tracks  with  fidelity  the  grooves  which  sound  has  recorded  on  the 
cylinder.  These  features,  combined  in  a  mechanism  of  the  ut- 
most accuracy  in  make  and  adjustment,  have  opened  for  the 


THE  TELEGRAPHONE 

phonograph  a  vast  field  in  the  business  world.  Some  of  the  great 
firms  and  companies  of  New  York  and  other  cities  now  use 
phonographs  instead  of  stenographers;  a  letter  or  a  contract  is 
dictated  to  a  revolving  cylinder  with  all  the  swiftness  of  ordinary 
speech.  Afterward  a  secretary  listens  to  the  reproducer  and 
writes  the  letter  or  contract  at  any  speed  desired.  On  occasion 
a  cylinder  bearing  a  message  may  be  sent  to  a  correspondent  who 
listens  to  its  words  as  sent  forth  from  his  own  phonograph,  no 
intermediate  writing  being  required.  Such  instruments  are  ex- 
tensively used  in  teaching  foreign  languages,  learners  being  free 
to  have  a  difficult  pronunciation  repeated  until  it  is  mastered. 
Mr.  Edison  has  much  improved  the  musical  records  familiar 
throughout  the  world;  these  are  now  produced  in  molds  of  gold 
with  a  delicacy  that  refines  away  the  scratchiness  of  tone  so  un- 
pleasant in  earlier  cylinders. 

As  the  fruit  of  rare  experimental  ability  Mr.  Valdemar  Poul- 
sen,   an    electrical    engineer   of    Copenhagen,    has   invented   the 
telegraphone.     This  instrument  proceeds  upon 
the  fact  that  the  electrical  pulses  of  the  tel-      Telephone  Mes- 
ephone,  minute  and  delicate  though  they  are,      sages  Recorded 
can   register   themselves   magnetically   upon   a         Dr ^^^^ 
moving   steel   wire   but   one-hundredth   of   an       Telegraphone. 
inch  in  diameter.    The  message  is  repeated  as 
often  as  the  wire  is  borne  between  the  poles  of  an  electro-magnet 
in  circuit  with  a  telephonic  receiver.     The  accompanying  figure 
shows  the  transmitter,  the  traveling  wire,  and  the  receiver  as  it 
repeats  a  message.    The  instrument  in  its  latest  form  is  illustrated 
opposite    page    314.      In    supplementing    the    telephone    most 
usefully,  this  apparatus  brings  a  fresh  competition  to  bear  upon 
the  telegraph.     In  many  cases  a  man  of  business  has  preferred 
to  telegraph    rather   than   to   telephone   a   message,   because   a 
telegram  as  a  written  record  affords  proof  in  case  of  error  or  dis- 
pute.   Now  suppose  that  through  a  telegraphone  a  broker  offers 
six  per  cent,  interest  for  a  loan ;  his  voice  impressed  on  the  wire, 
duly  preserved  for  reference,  identifies  him  as  securely  as  would 
his  signature  on  a  written  offer.    Take  a  different  case :  a  patient 
rings  up  a  physician  only  to  find  him  not  at  home;  a  message 
committed  to  a'few  yards  of  wire  is  listened  to  by  the  physician 


314 


EXPERIMENT 


the  moment  he  returns  to  his  office.  Take  an  example  of  yet  an- 
other service :  a  letter  may  be  dictated  at  Newark  and  recorded 
on  a  wire  in  Brooklyn,  and  there,  at  leisure,  be  put  upon  paper 


Transmitter 


^onfacf  Po/nf 


/fee fe  for  Mr* 


CorrfacfPo/nts 


Telegraphone. 
Diagram  of  working  parts. 


by  an  amanuensis.  Or,  better  still,  the  message  may  be  spoken 
upon  a  small,  revolving  disc  of  steel,  and  mailed  to  a  corre- 
spondent who  listens  to  its  words  as  they  roll  out  of  his  own 
graphophone.  Young  children  and  others  unable  to  write  may 
impress  discs  that  tell  their  story  to  correspondents  unable  to 
read.  So  compact  withal  are  the  records  of  this  instrument  that 
they  may  soon  give  us  not  only  music  from  the  concert-room,  and 
news  from  the  telegraph  office,  but  also  the  latest  popular  book. 
A  wire  or  a  disc  can  repeat  its  record,  vocal  or  musical,  hun- 
dreds of  times  without  loss  of  distinctness.  To  obliterate  this 


OFTHE 

UNIVERSITY 

OF 

C:*UFORN^ 


HANDWRITING  TELEGRAPHED     315 


record  it  only  is  necessary  to  pass  the  steel  between  the  poles  of 
a  strong  magnet. 

A  telephone  transmits  a  familiar  voice  so  that  its  tones  are  at 
or  ce  recognized.     By  electrical  means  a  telautograph  reproduces 
writing  at  a  distance  so  precisely  that  it  may 
be  as  readily  identified.     To  understand  how 
this  feat  is  accomplished  let  us  begin  with  the 
transmission  of  vertical  marks  varying  in  length. 


The 
Telautograph. 


Sending  Rheostat     j 
No.1. 

K 


£  To  ffece/vng  'Solenoid Hal- 


KLMN  0  PQ  RSTUV 


Receiving  Solenoid 
No.1. 

KLMNOPQ  RSTUV 


Sending  Rheostat 
No.  2. 


Receiving-  Solenoid 
No2. 


A,  sending  a  vertical  line  S  M  by  electricity. 
B,  sending  a  horizontal  line  S  M  by  electricity. 

This  task,  as  above  illustrated,  we  perform  by  sending  to  a 
receiving  pencil  a  current  varying  in  strength  between  limits 
which  correspond  to  the  variations  in  length  of  our  transmitted 
lines.  The  strength  of  this  current,  say  0.429  volt,  decides  where 
a  mark  will  begin ;  the  strength  of  that  current  in  rising  to  say  27.5 
volts,  decides  where  that  mark  will  end.  To  vary  the  strength 


316  EXPERIMENT 

of  the  current  as  desired  we  employ  a  square  rod  of  aluminium, 
tightly  covered  with  a  thin  copper  wire  insulated  by  silk  wrapping. 
We  place  this  rod  beside  our  tablet,  and  scrape  from  its  inner- 
most surface  the  silk  covering  so  as  to  leave  the  wire  bare,  while 
between  its  strands  the  silk  remains  intact  as  an  effective  insula- 
tion. Our  rod  is  now  a  rheostat,  whose  use  we  shall  presently 
discover.  We  are  wont  to  think  of  copper  as  a  good  conductor, 
and  so  it  is.  Used  in  stout  bars  or  thick  wires  it  exerts  but  little 
resistance  to  an  electric  current,  but  when  we  employ  a  wire  of 
but  1/200  of  an  inch  in  diameter,  about  the  thickness  of  the  paper 
on  which  this  is  printed,  the  narrowness  of  path  reduces  the 
pressure  of  a  current  so  much  that  in  the  course  of  375  feet  it 
falls  to  one  eighth.  In  like  manner  a  glass  tube  of  minute  di- 
ameter might  receive  at  one  end  water  under  extreme  pressure, 
and  at  a  yard  distance  send  out  a  mere  dribble.  The  copper  wire 
of  our  square  rod,  or  rheostat,  is  so  thin  that  when  connected  at 
K  with  a  source  of  no- volt  electricity,  at  V  this  voltage,  or 
pressure,  has  sunk  to  but  one  twentieth  of  a  volt. 

Let  us  suppose  our  rheostat  at  V  connected  with  a  circuit  ex- 
tended to  the  receiving  station.  A  wire,  kept  in  this  circuit,  and 
moving  up  and  down  with  our  pencil,  in  a  line  always  parallel 
with  the  side  of  our  tablet,  sends  to  the  receiving  station  a  cur- 
rent constantly  varying  in  its  pressure.  As  the  wire  passes  from 
S  to  M  the  transmitted  current  rises  from  0.429  to  27.5  volts. 

At  the  receiving  station  we  provide  means  whereby  the  current 
arriving  at  a  voltage  of  0.429  and  rising  to  27.5  will  mark  a 
vertical  line  the  length  of  S  M.  A  simple  device  for  this  purpose 
consists  in  a  hollow  coil  of  copper  wire,  or  a  solenoid,  as  elec- 
tricians call  it,  through  which  circulates  the  arriving  current,  the 
coil  being  free  to  be  drawn  as  a  shell  over  a  cylindrical  electro- 
magnet. The  degree  to  which  such  a  coil,  duly  attached  to  a  re- 
tractile spring,  is  drawn  over  a  suitable  electro-magnet,  depends 
upon  the  strength  of  the  current  circulating  in  the  coil.  In  the 
simple  instrument  we  are  using  let  us  assume  that  when  a  current 
of  no  volts  comes  in,  the  coil  moves  to  K,  the  end  of  its  path; 
that  when  a  current  of  6.875  volts  arrives,  the  coil  moves  to  O ; 
the  receiving  coil  and  the  sending  rheostat  being  marked  with 
the  same  divisions.  Our  receiving  coil  actuates  a  pencil  which 


CODING  AN  OPERATION  317 

accordingly  marks  a  line  of  the  same  length  and  direction  as  that 
set  down  on  the  tablet  of  the  sending  instrument. 

Let  us  next  transmit  between  these  two  stations  a  series  of 
horizontal  lines.  To  do  this  we  duplicate  our  first  apparatus.  We 
place  a  second  rheostat  along  the  foot  of  our  sending  tablet,  not 
along  its  side,  and  slide  a  second  wire  along  its  bared  surface 
with  motions  always  parallel  to  those  of  the  marking  pencil.  Thus 
a  second  current,  going  by  a  wire  of  its  own  to  the  receiving 
station  there  repeats  through  a  second  coil,  or  solenoid,  the  hori- 
zontal marks  of  our  sending  pencil. 

We  have  now  two  sets  of  apparatus,  alike  in  all  respects,  one 
sending  rheostat  at  right  angles  to  the  other;  one  receiving 
solenoid  at  right  angles  to  its  mate.  In  the  actual  telautograph 
the  rheostats  are  curved,  as  shown  in  the  picture  facing  page  318, 
and  they  are  so  joined  by  levers  that  the  up-and-down  and  side- 
wise  motions  of  writing  are  accurately  represented,  from  moment 
to  moment,  in  the  two  varying  currents  sent  afar.  As  these  cur- 
rents arrive  they  actuate  a  pencil,  similarly  furnished  with  levers, 
so  that  it  moves  in  a  path  which  exactly  corresponds  with  that  of 
the  sending  pencil.  The  apparatus  has  an  ingenious  ink  supply, 
and  a  device  to  shift  the  paper  as  filled  line  after  line.  In  its  basic 
features  the  telautograph  was  invented  by  the  late  Professor 
Elisha  Gray  of  Chicago.  Its  present  form  is  largely  due  to  the 
modifications  and  additions  of  Mr.  George  S.  Tiffany  of  New 
York.  The  instrument  is  giving  satisfactory  service  in  thou- 
sands of  banks,  factories,  hotels,  business  offices,  and  households. 
Its  records  at  both  ends  of  a  line  make  it  of  inestimable  value  in 
many  cases,  as  aboard  a  warship  where  orders  of  the  utmost  im- 
portance may  be  committed  to  its  tablets.  Exterior  and  interior 
views  of  the  instrument  are  given  facing  page  318. 

Only  a  few  machines  deal  with  writing  or  its  duplication,  most 
machines  perform   quite   other  tasks   at   first   wrought  by   the 
hands.      Inventors    have    always    gone    astray 
when  they  have  sought  to  imitate  a  hand  pro-   Machines  Cannot 
cess   with    anything   like   precision.      On   this     Directly  Imitate 
r-1,1         TVT      1,  r  T        j  Hands:  A  Task 

point  Sir  John  Fletcher  Moulton,  of  London,  Must  be 

says: — "Doubtless  you  have  often  had  to  send         "Coded." 
a  message  by  telegraph  to  some  distant  country 


318  EXPERIMENT 

to  which  the  rate  charged  per  word  is  high.  You  write  your  mes- 
sage as  tersely  as  may  be,  but  even  thus  its  length  is  formidable. 
You  resort  to  your  telegraphic  code.  It  tells  you  that  if  you  will 
change  the  phraseology  of  your  message  you  can  by  a  single 
code-word  represent  a  whole  phrase.  You  thereupon  set  to  work- 
to  recast  your  message  so  as  to  make  it  capable  of  being  expressed 
in  code-words.  When  you  have  done  so,  you  have  not  improved 
it  as  a  message.  It  is  less  terse  and  less  naturally  expressed.  If 
you  were  writing  and  not  telegraphing,  you  would  prefer  to  use 
it  in  its  original  form.  But  as  now  expressed,  each  of  the  phrases 
of  which  it  is  composed  can  be  sent  over  the  wires  in  the  form 
and  at  the  price  of  a  single  word,  and  the  cost  of  the  whole  is  but 
a  fraction  of  what  would  have  been  the  cost  of  the  message  as 
originally  framed.  It  has  been  cast  in  a  form  suitable  for  cheap 
telegraphing.  Just  so  with  the  inventor.  He  has  to  find  a  series 
of  operations  which,  in  their  totality,  are  equivalent  to  the  series 
of  the  hand  worker.  But  each  of  these  operations  in  itself  need 
not  be  such  as  would  in  hand  labor  be  suitable  or  even  practicable. 

"It  is  necessary  and  sufficient  for  him  that  they  are  suited  to 
the  new  conditions,  so  that  they  can  be  well  and  easily  done  by 
mechanism,  and  that,  taken  as  a  whole,  they  produce  the  same 
result  as  the  series  which  he  is  paralleling.  He  is  re-writing  the 
series  in  terms  suited  to  mechanism  just  as  the  message  was  re- 
written in  terms  suited  for  telegraphing.  The  meaning  of 
the  message  must  remain  the  same,  but  the  terms  used  to  express 
it  are  no  longer  those  most  naturally  used  in  writing  or  speaking, 
but  are  those  which  can  be  telegraphed  at  least  cost. 

"To  make  my  meaning  clear,  let  me  revert  to  the   familiar 

operation  of  sewing.     The  hand  process  is  plainly  unsuited  for 

mechanical    reproduction.      How    is    it    to    be 

Sewing  Coded        translated  into  an  equivalent  cycle  suitable  for 

in  a  Machine.  mechanism  ?  In  other  words,  how  is  it  to  be 
'coded'?  This  case  is  interesting,  inasmuch  as 
we  have  two  independent  solutions  worked  out  at  different  dates 
an'd  widely  different  in  nature.  The  earlier  invention  imitated  the 
hand  cycle  very  closely.  The  thumb  and  finger  of  the  right  hand 
in  the  human  being  were  replaced  by  pairs  of  pincers  capable  of 
taking  hold  of  the  needle  and  letting  it  free  again,  but  to  avoid 


TELAUTOGRAPH,  EXTERIOR. 


TELAUTOGRAPH,  INTERIOR. 


OF  THE 

UNIVERSITY 

OF 


THE  SEWING-MACHINE  319 

having  to  follow  the  intricate  movements  of  the  human  fingers 
in  the  operation  two  pairs  of  pincers  were  used,  one  on  each  side 
of  the  work,  which  passed  the  needle  backwards  and  forwards 
through  the  fabric  one  to  the  other.  Following  out  this  idea  the 
needle  was  pointed  at  both  ends  with  an  eye  in  the  middle,  and, 
as  in  hand  sewing,  it  carried  a  moderate  length  of  thread.  The 
pair  of  pincers  which  held  the  threaded  needle  advanced  to  the 
fabric  and  passed  through  it  to  the  other  pair  which  took  it  and 
retreated  so  as  to  draw  the  thread  tight  and  form  the  completed 
stitch.  To  form  the  next  stitch  the  work  was  moved  through  the 
proper  distance  and  the  same  process  was  gone  through,  the  line 
of  movement  of  the  needle  always  remaining  the  same. 

'There  is  not  much  'coding'  here.  The  new  cycle  imitates  the 
hand-worker  so  faithfully  that  it  benefits  little  by  the  advantages 
of  mechanical  action.  As  in  hand  work  it  can  only  sew  with 
moderate  lengths  of  thread,  and  must  therefore  have  the  needles 
re-threaded  at  intervals.  Its  superiority  over  hand  labor  is  there- 
fore so  slight  that  it  is  doubtful  whether  such  a  sewing  machine 
could  ever  have  competed  with,  much  less  replaced,  hand  work. 
But  it  has  one  great  merit.  The  needle  mechanism  is  capable  of 
being  re-duplicated  almost  without  limit,  and  the  movement  of  the 
work  which  is  necessary  to  direct  the  stitches  for  one  needle  will 
serve  equally  well  for  any  number  of  needles  working  parallel  to 
it.  Hence  the  machine  that  would  have  failed  as  a  sewing  ma- 
chine has  survived  and  proved  useful  as  an  embroidery  machine. 
The  work  is  stretched  between  two  rows  of  pincers  and  moved 
by  the  workman  according  to  the  stitches  of  the  pattern.  Each 
stitch  is  repeated  by  each  of  the  parallel  needles  which  work  side 
by  side  at  convenient  distances,  and  thus  as  many  copies  of  the  pat-  . 
tern  are  simultaneously  produced  as  there  are  needles.  Each  is  a 
perfect  facsimile  of  all  the  others,  and  as  each  copies  faithfully 
the  errors  of  the  workman,  this  machine  is  entitled  to  the  proud 
boast  that  its  productions  possess  all  the  defects  of  hand  work— 
an  essential  we  are  told  of  artistic  beauty. 

"What  is  the  cause  of  the  comparative  failure  of  this  attempt 
at  a  sewing-machine?  It  is  evident  that  it  is  due  to  the  retention 
of  the  feature  of  the  hand  operation  by  which  the  needle  is  passed 
from  one  holding  mechanism  to  the  other.  The  inventors  of  the 


320  EXPERIMENT 

modern  sewing-machine  on  the  one  hand  decided  to  work  with  a 
needle  fixed  in  its  holder  and  never  leaving  it  throughout  the 
operation.  It  at  once  followed  that  the  needle  and  thread  must, 
on  the  back  stroke,  return  through  the  same  hole  through  which 
they  had  entered  the  fabric,  so  that  no  stitch  could  be  formed  un- 
less some  obstacle  were  interposed  to  the  return  of  the  thread. 
Here  the  two  famous  and  successful  forms  of  the  machine  parted 
company.  Both  placed  the  eye  at  the  point  of  the  needle  that  the 
stroke  might  not  be  needlessly  long,  but  while  the  lock  stitch 
machine  used  a  second  thread  to  provide  the  necessary  obstacle, 
the  chain  stitch  machine  availed  itself  of  a  loop  of  the  original 
thread  for  that  purpose.  Thus  in  the  lock  stitch  machine  the  sub- 
stituted cycle  became  as  follows  : — 

(1)  The  work  is  moved  under  the  needle  for  the  new  stroke. 

(2)  The  needle  (which  has  an  eye  at  its  point  through  which 
the  thread  passes)  pierces  the  fabric  carrying  with  it  the  thread. 

(3)  A  second  thread  is  passed  between  the  thread  and  the 
needle  (by  means  of  a  shuttle  or  its  equivalent)  when  the  needle 
is  at  its  lowest  position. 

(4)  The  needle  returns  while  a  take-up  retracts  the  thread  so 
as  to  tighten  the  stitch. 

"This  cycle  would,  for  hand  work,  be  immeasurably  more  com- 
plicated and  difficult  than  ordinary  sewing,  but  it  consists  of 
operations  mechanically  easy  of  performance  in  swift  and  accu- 
rately timed  sequence,  and  as  the  whole  of  the  thread  in  use. has 
no  longer  to  be  passed  from  one  side  of  the  fabric  to  the  other  as 
each  stitch  is  made,  it  has  brought  with  it  the  all-important  ad- 
vantage of  our  being  able  to  work  with  a  continuous  thread. 
Here,  then,  is  a  magnificent  example  of  'coding.'  It  is  not  to  be 
wondered  at  that  the  machines  which  it  has  given  to  the  world 
are  in  well-nigh  universal  use,  and  have  profoundly  modified 
both  our  social  and  industrial  economy." 

One  of  the  supreme  inventions  of  all  time  is  the  mower  of  Obed 

Hussey,  of  Maryland,  devised  in  1833,  and  afterward  adapted  to 

reaping.    In  the  primitive  reaping  of  tall  grain 

Obed  Hussey       one  hand  keeps  the  stalks  upright,  while  the 

and  His  Mower,      other   hand   cuts   these    stalks    with    a   scythe. 

Hussey,  in  a  masterpiece  of  "coding,"  arrayed 


HUSSEY'S  MOWER 


821 


Obed  Hussey's  mower 
or  reaper. 


metal  fingers  which  keep  the  grain  from  bending,  while  vibrating 

knives  sever  the  stalks.     To  this  day  his  invention  remains  the 

core  of  millions  of  mowers  as  well  as  reapers ;  it  has  economized 

labor  to  an   extent  beyond   estimate, 

and  by  shortening  the  time  required 

in  harvesting  has  saved  many  million 

bushels    of    grain     which    otherwise 

would   have  been   destroyed   by   bad 

weather. 

Not  a  few  inventors  of  the  first 
mark  are  found  among  the  men  of 
great  ability  who  unite  training  in  two 
distinct  fields  of  science,  whose  al- 
liances they  thoughtfully  cultivate. 

Thus  Helmholtz,  at  once  a  physician 
and  a  physicist,  devised  the  ophthalmo- 
scope, that  simple  instrument  for  observing  the  interior  of  the 
eye.  On  a  plane  less  lofty  an  inventor's  success  may  turn  on  his 
width  of  outlook,  his  intimacy  with  fields 

remote  from  the  home  acre,  so  that  he  may        New  Modes 

of  Attack. 
gainfully  ally  two  arts  or  processes  that,   to 

a  casual  glance,  seem  utterly  unrelated  or  unrelatable.  When 
a  pneumatic  tube  between  a  post-office  and  a  railroad  station 
is  obstructed,  there  would  seem  to  be  no  promise  of  aid  in  a 
fire-arm.  But  snapping  off  its  blank  cartridge  at  the  open  end  of 
the  tube  gives  back  an  echo  through  the  air  within  the  tube;  in 
measuring  the  interval  between  touching  the  trigger  and  hearing 
the  echo,  there  is  news  as  to  where  the  tube  is  choked,  the  velocity 
of  sound  in  air  being  known.  From  the  labors  of  a  postmaster 
let  us  turn  to  those  of  an  apothecary,  who  pounds  and  grinds  his 
drugs  in  a  mortar  which  has  descended  from  the  day  when  it 
reduced  grain  to  flour.  The  grindstones  which  succeeded  the 
mortar  were  only  in  recent  years  ousted  by  Hungarian  rollers  of 
steel  which  separate  the  constituents  of  grain  with  a  new  per- 
fection. Their  excellence  consists  in  imitating  the  crushing  of 
the  mortar,  not  in  attempting  the  grinding  of  the  familiar  burrs. 
The  miller's  practice  in  one  particular  has  given  the  postmaster 
a  hint  of  value.  In  a  flour-mill  a  cheap  and  sufficient  motor  is 


322  EXPERIMENT 

simple  gravity  as  the  products  pass  from  one  machine  to  the  next. 
At  the  very  outset  the  wheat  is  taken  by  conveyors  to  the  top 
floor,  whence  its  products  descend,  stage  by  stage,  impelled  by 
gravity  alone,  until  the  finished  and  barreled  flour  rolls  into  ship- 
ping rooms  beside  the  railroad  tracks.  This  principle  has  been 
adopted  at  the  Chicago  Post-office,  where  the  mails  as  received 
are  borne  to  the  top  floor,  thence,  by  gravity,  they  take  their  way 
as  sorted  and  re-sorted,  to  the  ground  floor  where  they  are  finally 
disposed  of. 

In  a  field  somewhat  parallel  is  the  modern  art  of  designing  the 
layout  of  a  great  manufacturing  plant  so  that  the  material  shall 
travel  as  little  as  possible  between  its  entrance  and  its  exit.  In  a 
well  planned  ship-yard  the  machines  are  so  placed  that  the  steel 
plates,  bars  and  girders,  the  planks  and  boards,  move  continuously 
from  one  machine  to  its  neighbor,  ending  at  last  by  reaching  the 
building  berth. 

Shears  for  metal,  cutting  scissors-fashion,  have  long  been 
familiar;  the  Pittsburg,  Fort  Wayne  and  Chicago  Railroad  em- 
ploys the  Murphy  machine,  on  the  same  principle,  to  cut  up  old 
ties  and  bridge  timbers  intended  for  fuel.  The  upper  moving 
blade  is  set  about  an  inch  out  of  line  from  the  lower  fixed  blade, 
so  as  to  allow  spikes  or  bolts  to  pass  through  without  injuring 
the  machine.  In  dividing  cord  wood  for  stoves  and  furnaces  a 
machine  of  this  kind  might  be  used  instead  of  a  saw. 

It  is  by  perfect  means  of  subdivision  that  new  and  cheap 
materials  for  writing  and  printing  are  now  produced.  The  leaves 
offered  by  the  papyrus  to  scribes  were  used  for  centuries,  so  that 
the  plant  has  given  its  name  to  paper  now  made  from  fibres  of 
cotton,  linen,  or  wood,  finely  divided,  thoroughly  mixed,  and 
squeezed  between  rollers  much  as  if  paste.  Paper  from  its 
smoothness,  its  absence  of  grain  and  its  low  price,  is  far  pref- 
erable to  papyrus  leaves  or  vellum.  Its  manufacture  has  been 
copied  in  diverse  new  industries.  Wood  ground  to  powder, 
worked  into  pulp,  molded  into  pails,  tubs  and  the  like,  is  satu- 
rated with  oil  to  produce  wares  of  indurated  fibre.  A  pail  thus 
manufactured  will  not  split  apart  in  dry  weather  when  empty,  or 
absorb  liquids,  and  it  is  as  easily  kept  clean  as  glass. 

While  wood  has  thus  found  a  rival  in  pulp,  stone  has  a  new 


LINOTYPY 


323 


competitor  much  more  formidable.  Pavements  and  piers  are 
often  needed  in  long  stretches,  without  joints  for  the  admission 
of  rain  or  frost.  The  demand  is  met  by  cements  and  concretes 
easily  laid  in  un jointed  miles.  These  materials  when  strengthened 
with  skeletons  of  steel  find  many  uses ;  a  brief  survey  of  them  is 
given  in  this  book.  A  sister  product,  terra  cotta,  baked  at  high 
temperatures,  is  now  molded  in  beautiful  designs  not  only  for 
tiles,  but  as  walls,  cornices,  finials,  vases,  hearths,  and  statuary. 
Clay  as  tablets  was  one  of  the  first  mediums  of  the  printer's 
art,  an  art  of  late  years  exposed  to  many  a  surprise  from  unex- 
pected invaders.  Composition  is  now  performed 
by  machines  of  various  models,  one  of  them  Linotype  and 

1     •         i,  i     i      »     1-  i         j  r  Its  Use  of 

being  Mergenthaler  s  linotype,  as  employed  for          Wedges 
this  book.     In  effect  this  machine  is  a  caster 
rather  than  a  compositor,  and  recalls  the  chief  tasks  of  the  type- 
foundry.    As  an  operator  touches  its  keys  he  releases  a  succession 
of  matrices,  from  which  is  cast  a  line  as  a  unit.    In  its  latest  forrr. 


Mergenthaler  linotype,  showing  five  double  wedges  for  justification. 


this  machine  enables  the  operator  to  change  instantly  from  one 
font  to  another,  introducing  roman,  italic,  and  black  face  type  in 


324 


EXPERIMENT 


M 


the  same  line  at  will.  Intricate  book,  tabular  and  pamphlet  mat- 
ter, with  chapter  headings,  titles,  or  marginal  notes  may  in  this 
new  model  be  set  up  at  a  speed  four  to  six  times  quicker  than 
hand  composition. 

An  illustration  shows  the  two-letter  matrices  of  a  special  Mer- 
genthaler  machine.  The  upper  is  usually  a  body  character  and 
the  lower  an  italic,  a  small  capital  or  a  black  face.  These  lower 
matrices  are  lifted  a  little  by  a  key  so  as  to  come  in  line  with  upper 
matrices.  In  this  way  the  compositor  has  at  command  two 
distinct  fonts.  Groove  E  receives  the  ears  of  the  matrices.  In  a 
normal  position  D  receives  the  ears  of  the  matrices  elevated  to 
produce  the  secondary  characters.  In  this  way  the  matrices  are 
held  in  position  as  casting  proceeds.  Five  double-wedge  justifiers 
will  be  observed  between  the  matrices.  These  devices,  invented 

by  J.  W.  Schuckers,  form  an  essential 
part  of  the  machine.  Justification, 
let  the  reader  be  reminded,  is  so 
spacing  the  contents  of  a  line  that  it 
shall  neatly  end  with  a  word  or  syl- 
lable. In  typewritten  manuscript  the 
lack  of  justification  leaves  the  ends 
of  lines  jagged  and  unsightly.  Mr. 
Schuckers  at  the  end  of  every  word 
places  a  pair  of  wedges.  When  the 
operator  is  close  to  the  end  of  a 
line  he  pushes  in  the  whole  row  of 
wedges  in  that  line ;  the  outer 
sides  of  each  pair  remain  always  parallel,  and  as  pushed  in  these 
outer  sides  are  just  sufficiently  forced  apart  to  space  out  the  line 
with  exactitude.  To  lift  a  table  or  a  desk,  and  at  the  same  time 
keep  it  always  level,  we  may  use  pairs  of  wedges  in  the  same 
manner;  they  must,  of  course,  be  much  larger  and  thicker  than 
those  used  in  linotypy.  See  next  page  for  an  illustration. 

To-day  a  book  may  be  reproduced  without  any  recourse  what- 
ever to  the  type  long  indispensable.  A  photographer  takes  the 
volume,  and  repeats  it  in  pages  of  any  size  we  wish,  dispensing 
not  only  with  the  type-setter  or  the  type-caster,  but  even  with 


Surfaces  A  and  B  ere  \ 
parallel  with  each  other] 


m 

J.  W.  Schuckers'  double- 
wedge  justifier. 


WEDGES  IN  A  NEW  SERVICE       325 

the  proofreader,  since  a  camera  furnishes  an  exact  fac-simile  of 
the  original  work.  If  the  book  is  illustrated,  a  further  economy 
is  enjoyed;  its  pictures  are  copied  as  faithfully  and  cheaply  as  the 
letterpress. 


B 


A,  two  wedges  partly  in  contact 
B,  two  wedges  fully  in  contact,  outer  sides  parallel. 


Copying  and 
Decorating. 


A  feat  which  is  a  mere  trifle  as  compared  with  reproducing  a 
book  by  photography,  turns  upon  a  loan  from  an  old  resource. 
Confectioners  from  time  immemorial  have 
squeezed  paste  out  of  bags  through  apertures  Ingenuity  in 
into  ornaments  for  wedding  cakes  and  the 
like.  With  similar  bags  decorators  force  a 
thin  stream  of  plaster  into  a  semblance  of  flowers,  fruits,  and 
arabesques  on  their  ceilings  and  cornices.  On  the  same  plan, 
with  pressure  more  severe,  soap  is  forced  from  a  tank  through  a 
square  opening  to  form  bars  for  the  laundress.  Increasing  the 
pressure  once  again,  clay  for  bricks  is  urged  forth,  to  be  divided 
into  lengths  suitable  for  the  kiln.  Lead  pipe  is  manufactured  on 
the  same  principle,  recalling  the  production  of  macaroni.  A 
further  step  was  taken  by  Alexander  Dick,  the  inventor  of  Delta 


326  EXPERIMENT 

metal ;  by  employing  hydraulic  pressure  on  metals  at  red  heat  he 
poured  out  wires  and  bars  of  varied  cross-sections,  superseding 
the  method  of  drawing  through  dies. 

Cold  as  well  as  heat  may  be  employed  in  a  novel  manner.    The 
flesh  of  birds,  beasts,  and  insects  is  now  frozen  hard,  so  as  to  be 
sliced  into  extremely  thin  sections  clearly  show- 
Frost  as  a  -mg  tjle  details  Of  structure.     How  a  freezing 
Servant.  .  ,  ,,  ,  r         • 
process  may  aid  the  miner  was  shown  first  in 

Germany  in  1880,  when  Hermann  Poetsch,  a  mining  engineer, 
had  to  sink  a  shaft  near  Ashersleben,  to  a  vein  of  coal,  where, 
after  excavating  100  feet,  a  stratum  of  sand  eighteen  feet  thick, 
overlying  the  coal,  was  encountered.  It  occurred  to  Poetsch  that 
the  great  difficulty  occasioned  by  the  influx  of  water  through  the 
sand  could  be  overcome  by  solidifying  the  entire  mass  by  freezing. 
To  do  this,  he  penetrated  the  sand  to  be  excavated  with  large  pipes 
eight  inches  in  diameter,  sunk  entirely  through  it  and  a  foot  or 
two  into  the  underlying  coal.  These  were  placed  in  a  circle  at 
intervals  of  a  metre,  and  close  to  the  periphery  of  the  shaft.  They 
were  closed  at  the  lower  end.  Inside  each  of  these  and  open  at  its 
lower  end  was  a  pipe  an  inch  in  diameter.  This  system  of  pipes 
was  so  connected  that  a  closed  circulation  could  be  produced 
down  through  the  small  pipes  and  up  through  the  large  ones.  An 
ice-machine,  such  as  brewers  use,  was  set  up  near  by  and  kept  at 
a  temperature  below  zero  Fahrenheit.  A  tank  filled  with  a  solu- 
tion of  chloride  of  magnesium,  which  freezes  at  —40°  Fahr.,  had 
its  contents  circulated  through  the  ground  pipes  described. 
Thermometers  placed  in  pipes  sunk  in  the  mass  of  sand  showed 
51.8°  Fahr.  at  the  beginning  of  the  process.  The  circulation  was 
kept  up  and  on  the  third  day  the  whole  mass  was  frozen.  Within 
the  continuous  frozen  wall  the  material  was  excavated  without 
damage  from  caving  in  or  inflow  of  water.  The  freezing  entered 
the  coal  three  feet,  and  to  a  distance  six  feet  outside  the  pipes. 
The  circulation  was  kept  up  until  the  excavation  and  walling  were 
complete.  On  a  somewhat  similar  plan  tunnels  have  been  bored 
through  difficult  ground.  Of  late  years  at  Detroit,  and  elsewhere, 
serious  breaks  in  water-mains  have  been  repaired  after  a  freezing 
process  has  solidified  the  stream. 


LIGHT  IN  NEW  DISCLOSURES      327 


Light,  as  well  as  heat  and  cold,  is  to-day  bidden  to  perform 
new  duties.     It  was  long  ago  observed  that  polarized  light  as  it 
takes  its  way  through  transparent  crystal  or  glass  clearly  reveals 
in  areas  of  variegation,  any  strains  to  which  the  crystal  or  glass 
may  be  subjected.     Of  late  this  fact  has  been  applied  with  new 
skill  to  investigating  strains  in  engineering  structures.     A  model 
in  glass,  carefully  annealed,  is  placed  in  the  path  of  a  beam  of 
polarized  light.    By  shifting  the  points  of  appli- 
cation and  of  support,  by  loading  the  structure      Polarized  Light 
more  or  less,  and  here  or  there,  the  distribution        and  X-Rays. 
of  stresses  and  strains  is  directly  shown  to  the 
eye.     In  this  way  curved  shapes  of  various  kinds  have  been  in- 
vestigated, as  well  as  bodies  in  which  Hooke's  law  of  the  strict 
proportionality  of  strain  to  stress  does  not  apply.     Photographs 
taken  by  this  method  show 
the   distribution   of   stresses 
in    rings    subjected    to    ex- 
ternal    compression,     crank 
shafts,       and       car-coupler 
hooks.    It  would  be  interest- 
ing thus  to  compare  stand- 
ard types  of  girders,  trusses, 
and     bridges,     as     well     as 
arches    of    various     forms, 
both  regular  and  skew. 

Polarized  light,  which  when  first  discovered  seemed  nothing 
more  than  a  singular  and  quite  sterile  phenomenon,  has  other  uses 
of  great  importance.  It  tells  the  chemist  how  much  sugar  a  given 
solution  contains ;  it  displays  the  inner  architecture  of  rocks  when 
these  are  sawn  into  thin  sections. 

Even  more  valuable  than  polarized  light  are  the  X-rays  dis- 
covered by  Professor  Rontgen.  One  of  their  latest  uses  is  to 
reveal  impurities  and  air  bubbles  in  electric  cables,  affording  a 
procedure  much  simpler  and  easier  than  to  employ  electrical  in- 
struments. In  the  production  of  X-rays  and  similar  rays  a  tube 
as  nearly  vacuous  as  possible  is  employed.  As  an  aid  in  removing 
air  Professor  James  Dewar,  of  Cambridge  University,  has  recently 


Polarized  light  showing  strains  in  glass. 


328  EXPERIMENT 

adopted  cocoanut  charcoal  with  remarkable  success.  He  subjects 
it  to  the  intense  cold  of  liquid  air,  then  establishing  communica- 
tion between  a  receptacle  rilled  with  this  charcoal  and  a  bulb  ex- 
hausted to  one  fourth  of  the  ordinary  atmospheric  pressure,  he 
has  air  so  tenuous  that  an  electric  spark  passes  through  it  with 
difficulty.  So  much  for  developing  the  long  known  affinity  of 
charcoal  for  gases,  a  property  which  increases  in  degree  as  tem- 
peratures fall. 


CHAPTER  XXII 

AUTOMATICITY  AND  INITIATION 

Self-acting  devices  abridge  labor  .  .  .  Trigger  effects  in  the  laboratory, 
the  studio,  and  the  workshop  .  .  .  Automatic  telephones  .  .  .  Equi- 
librium of  the  atmosphere  may  be  easily  upset. 

AT  this  place  we  may  for  a  little  while  consider  a  few  funda- 
mental principles   of  construction  whereby  inventors   have 
economized  material,  labor  and  energy  by  making  their  devices 
self-acting,  and  by  so  poising  a  contrivance  that  a  mere  touch  at 
the  right  time  and  place  sets  it  going. 

Humphrey  Potter  was  a  boy  whose  duty  obliged  him  to  open 
and  shut  the  valves  of  a  Newcomen  steam-engine  as  it  slowly 
went  its  rounds.  He  was  a  human  sort  of  boy, 
who  liked  play  better  than  his  irksome  task,  so  Steam  Engines, 
he  found  a  way  to  rid  himself  of  the  drudgery 
of  constantly  moving  his  valve-handles  to  and  fro.  He  tied  a  rod 
to  the  walking  beam  in  such  wise  that  it  opened  the  valve  at  the 
proper  moment,  and,  at  another  point  in  its  circuit,  when  neces- 
sary, closed  it.  Then  and  only  then  did  the  steam-engine  become 
self-acting-.  In  the  best  modern  types  of  engine  this  automaticity 
goes  far  indeed.  Not  only  does  the  mechanism  pump  water  as 
required  into  both  the  boiler  and  the  condenser,  it  shuts  off  steam 
instantly  when  the  engine  moves  too  swiftly,  and,  when  the  engine 
speed  is  sluggish  the  port  betwixt  boiler  and  cylinders  is  opened 
to  the  full.  And  further:  automatic  stokers  bear  coal  into  the 
furnace  at  a  rate  which  varies  with  the  demand,  should  the  steam 
pressure  fall  through  an  undue  call  for  power,  then  an  extra 
quantity  of  coal  is  borne  upon  the  grate-bars.  When  oil  is  the  fuel 
automatic  stoking  is,  of  course,  at  its  best,  there  being  neither 
cinders  nor  ashes  to  be  removed— a  duty,  by  the  way,  which  in 
large  central  stations  requires  extensive  machinery,  all  automatic. 


330 


AUTOMATICITY 


The  essence  of  automaticity  is  that  mechanism  at  a  certain,  pre- 
determined point  in  an  operation  shall  perform  a  required  act. 

Thus,  to  take  the  common  example  of  a  striking 
Self-winding          dock  .  at  the  end  of  each  hour  a  detent  ig  pulled 

so  as  to  release  a  hammer  which  hits  a  gong  the 
proper  number  of  times.  Let  us  suppose  the  clock  to  be  driven  by 
a  weight  or  a  spring  in  the  ordinary  way ;  every  day  or  every  week 
the  weight  or  spring  will  require  to  be  wound  up.  In  time-pieces 
of  a  new  variety  the  period  during  which  no  attention  whatever  is 
needed  is  lengthened  to  a  year.  The  Self-winding  Clock  Com- 
pany, of  Brooklyn,  New  York,  makes  a  clock  which  is  driven  by 
a  fine  spring,  much  like  a  common  clock ;  that  spring  every  hour 
is  automatically  wound  up  by  a  tiny  electric  motor  connected  with 
a  small  battery  in  the  clock  case.  An  attachment  is  provided  by 
which,  through  the  wires  of  the  Western  Union  Telegraph  Com- 
pany, the  clock  is  every  hour  regulated  to  the  standard  time  of  the 
National  Observatory  at  Washington.  The  charge  for  this  service 
is  one  dollar  a  month. 

To-day  a  designer  always  seeks  to  make  a  machine  self-acting, 
to  limit  the  operator's  task  to  starting,  directing,  and  stopping,  all 
with  the  utmost  facility  and  the  least  possible 
Looms  and          exertion.    So  far  has  success  gone  in  this  direc- 
tion that  a  single  tender  in  a  cotton-mill  may 
have  charge  of  sixteen  Northrop  looms,  and  go  to  dinner  leaving 
all  at  work.    In  case  that  a  thread  breaks  in  any  of  them,  the  loom 


Stop-motion. 


FEEDING  MECHANISM 


331 


will  stop  of  itself  and  no  harm  will  be  done,  the  only  loss  consist- 
ing in  the  time  during  which  the  wheels  and  levers  have  lain  idle. 
A  stop-motion  at  its  simplest  is  a  fork  through  which  the  thread 
travels ;  as  the  thread  moves  forward,  the  fork  is  bent  downward 
extending  a  light  coiled  spring ;  should  the  thread  break,  the  spring 
instantly  lifts  the  fork,  which  in  rising  stops  the  machine. 

Among  the  most  noteworthy  automatic  machines  are  the  presses 
which  take  a  continuous  roll  of  paper,  print  both  sides,  cut  it  into 
leaves,  fold  these,  paste  them  at  the  back,  and,  if  desired,  sew  them 
together  and  attach  a  cover.  Such  a  press  stands  for  the  union  of 
several  operations  once  distinct ;  it  argues  great  ingenuity,  careful 
planning,  with  paper  exactly  adapted  to  the  stresses  it  must  en- 
counter, while  the  ink  is  of  a  quick-drying  variety. 

Binding  operations  and  a  good  deal  of  printing  have  to  deal 
with  separate  sheets  of  paper  or  card.  To  feed  these  to  presses, 
folders  or  binders  was  for  many  years  a  task 
for  the  hand.  To-day  the  Dexter  Folder  Com-  The  Dexter 
pany,  of  New  York,  in  a  diversity  of  machines 
supersedes  this  toil  by  an  ingenious  imitation  of 
manual  movements.  The  uppermost  sheet  of  paper  in  a  pile  is  for 
a  moment  held  down  at  A  by  a  rubber  finger,  during  that  moment 
a  small  rubber  roller  B  slightly  buckles  the  sheet ;  at  the  same  time 


Feeding 
Mechanicm. 


Dexter  feeding  mechanism. 
Dexter  Folder  Co..  New  York. 


332  AUTOMATICITY 

an  airblast  lifts  the  sheet  from  its  pile ;  that  done,  all  in  a  twinkling, 
finger  A  rises  and  the  sheet  passes  either  into  a  press  or  a  folding 
machine.  So  nicely  limited  is  the  pathway  for  the  paper  that  no 
more  than  one  sheet  can  pass  at  a  time;  if  two  or  more  sheets 
present  themselves,  the  feeding  mechanism  stops,  bringing  the 
press  or  folder  to  a  standstill.  As  each  sheet  passes  from  under 
the  rubber  fingers,  the  table  bearing  the  pile  of  paper  is  lifted  by 
just  one  thickness  of  paper. 

Mr.  James  Douglas,  president  of  the  Copper  Queen  Company, 
New  York,  thus  describes  automatic  devices  in  metallurgy :  "The 

gold  mill,  with  its  series  of  automatic  opera- 
Self-Actmg          tions,  is  the  offspring  of  Californian  ingenuity. 

^n  ^  manual  labor  is  almost  entirely  replaced  by 

ocular  labor,  for  superintendence  and  not  work 
is  the  function  of  the  mill-hands.  The  ore,  dumped  into  the 
breakers,  falls  into  large  pockets,  whence  it  slides  into  automatic 
feeders,  which  supply  the  stamps  with  regulated  quantities.  The 
free  gold  is  partly  extracted  by  liquid  mercury  in  the  mortars,  and 
by  copper  plates  attached  to  their  sides,  and  partly  on  an  apron  of 
amalgamated  copper  plates,  over  which  crushed  pulp  flows  as  it 
issues  from  the  battery  screen.  Automatic  vanners  receive  the 
tailings,  separate  the  sulphurets,  and  discharge  the  waste.  When 
the  power  is  water,  the  stream  is  divided  to  Pelton  wheels,  coupled 
to  the  separate  groups  or  even  pieces  of  machinery.  The  absence 
of  intermediate  running  gear  increases  not  only  the  sense,  but  the 
reality  of  automaticity,  and  makes  a  skilfully  arranged  and  thor- 
oughly equipped  Californian  mill  one  of  the  triumphs  of  modern 
mechanical  metallurgy." 

An  interesting  field  of  ingenuity  concerns  itself  with  giving 
work  the  right  start  and  a  simple  path.    A  tear  in  a  sheet  of  paper 

accurately  follows  the  line  of  a  directive  crease. 
Directive  Paths.      Postage  stamps,  small  as  they  are,  we  readily 

detach  from  one  another  because  perforations 
give  direction  to  the  tearing  strain.  So  the  quarryman  takes  care 
to  cut  a  V-shaped  groove  in  the  rock  he  is  to  break,  along  which 
groove  the  break  takes  its  way.  A  bolt  when  over-strained  will 
break  in  the  thread,  whether  this  be  the  smallest  section  or  not, 


THE  PIANOLA  333 

because  the  thread  is  a  starting  point  for  a  parting".  A  rod  of 
glass  is  divided  with  a  slight  jar,  provided  that  a  groove  has  been 
filed  in  its  surface.  In  all  this  there  is  shown  the  importance  of 
avoiding  in  a  casting,  or  forging,  such  minute  cracks  as  under 
severe  strain  may  lead  to  rupture. 

Within  the  past  ten  years  automatic  musical  instruments  have 
been  much  improved  and  are  now  well  established  in  public  favor. 
Not  a  few  teachers  of  mark  use  them  in  their 
schools  as  a  means  of  familiarizing  their  pupils         The  Pianola, 
with  the  best  music.    All  these  instruments  af- 
ford an  opportunity  for  expression  on  a  performer's  part ;  the  ef- 
fects producible  by  a  practiced  performer  are  remarkable,  and  give 
color  to  the  prediction  that  automatic  music  may  have  a  parallel 
history  with  that  of  the  photograph,  which   has  at  last  attained  a 
truth   and  beauty  which  bring  it  to  a  rivalry  with  the  art  of  the 
painter. 

From  the  educational  series  issued  by  the  ^Eolian  Company, 
New  York,  a  few  notes  from  Schumann's  "Traumerei"  are  here 
given,  together  with  these  notes  as  they  appear  on  a  music  roll  for 
the  Pianola. 

A  Pianola  is  operated  by  suction,  through  the  exhaustion  of  air 
from  a  bellows  normally  distended  by  springs  as  shown  in  5  in  the 
accompanying  illustration.  The  exhauster  is  operated  by  the 
pedal  i ;  the  board  3,  with  its  small  bellows,  exhausts  the  air  from 
5  in  the  chest  7  by  a  series  of  valves  not  shown  in  detail.  When 
the  air  is  pumped  from  5  by  the  motion  of  exhauster  3,  this  bel- 
lows collapses  notwithstanding  the  retractile  spring  6.  The  ex- 
haust condition  may  now  operate  upon  any  chamber  of  the  whole 
mechanism  through  trunk  7  and  pipe  8.  When  a  perforation  in  a 
music  sheet  16  passes  over  its  corresponding  duct  in  tracker  15, 
air  is  admitted  through  tube  14,  which  relieves  the  diaphragm  in 
chamber  9,  made  of  a  very  thin  piece  of  leather,  upon  which  rests 
the  stem  of  valve  n.  Owing  to  the  suction  in  chamber  9  this 
diaphragm  instantly  raises  and  shuts  the  outer  port  23  by  means 
of  valve  n,  giving  a  free  communication  from  pipe  8  through 
chambers  9  and  12,  to  the  striking  pneumatic  13  which  collapses, 
and  through  pitman  19  and  finger  20  strikes  the  key.  As  soon  as 


334 


AUTOMATICITY 


the  unperforated  part  of  the  music  sheet  has  passed  over  the  hole 
15  in  the  trackerboard,  the  flow  of  air  through  pipe  14  is  cut  off 


Moderate.  (M.M.  J  =  iofr. 


PIANO. 


Schumann's  "Traumerei,"  first  notes. 

and  the  pressure  on  the  small  diaphragm  in  chamber  9  has  ceased 
to  be  operative,  and  valve  1 1  immediately  drops  and  allows  air  to 


* 

\ 

\ 

/•i 

1 

s 

*d<» 

\ 

0   «° 

•" 

.J 

/.         MF      » 

, 

,y 

''" 

ll 

ftd. 

o  = 

° 

' 

^ 

(e) 

)       ; 

Beginning  of 

Roll. 

(b) 

,  : 

T") 

\             r^(d) 

UQ^ 

(a)  Red.  put on damper  pedal;  %  take  off pedaf. 

(b)  Expression  Line. 

(c)  Mefrosfyle  Line. 

(d)  Expression  Marks. 

(e)  Roll 'Perforations. 
\,2,3,z't<:."Tfcme'or'phrase*mmber3  corresponding  to  numbers  on  muslt. 

First  notes  of  the  "Traumerei"  on  a  Pianola  roll. 


AUTOMATIC  TELEPHONY 


335 


pass  into  striking  pneumatic  13,  through  port  23,  so  that  pneumatic 
13  and  the  key  levers  come  back  to  their  normal  positions. 


Mechanism  of  Pianola. 

Much  self-acting  machinery  employs  electricity.  By  virtue  of 
this  wonderful  agent  the  Automatic  Electric  Company  of  Chicago 
instals  telephonic  systems  which  enable  a  sub- 
scriber to  connect  himself  directly  with  any 
other  subscriber,  without  the  intervention  of  an 
operator  at  the  central  station.  As  exemplified  in  large  exchanges 
such  as  those  of  Dayton,  Ohio,  and  Grand  Rapids,  Michigan,  the 
apparatus  is  complex  in  its  detail.  If  we  take  a  small  exchange, 


Automatic 
Telephones. 


CALLING  6  ON  THE  AUTOMATIC  TELEPHONE 
AUTOMATIC  ELECTRIC  Co.,  CHICAGO. 


CHEMICAL  TRIGGERS 

Such  as  that  of  a  village  with  100  instruments,  we  may  readily 
understand  the  main  principles  of  the  method.  Let  us  suppose 
that  No.  I  of  our  instruments  is  at  the  Post  Office,  where  the 
Postmaster  wishes  to  call  58.  With  a  finger  he  moves  hole  5  in  the 
dial  plate  of  his  calling  instrument  (see  the  page  opposite  336  ) 
until  it  touches  a  protruding  stud.  Then  he  lets  go,  when  the  dial 
returns  to  its  original  position.  In  returning  it  sends  five  impulses 
to  the  central  office  where  a  vertical  rod  is  lifted  five  notches  (see 
illustration,  page  336.  He  next  moves  hole  8  to  the  stud  and  lets 
go.  This  time  the  rod  turns  through  a  considerable  part  of  its 
semicircle  of  motion.  The  instant  its  journey  is  at  an  end  a  tiny 
metallic  arm  flies  out  and  connection  is  completed  with  a  wire  run- 
ning to  58,  ringing  his  bell.  In  case  he  is  busy,  a  buzzing  noise 
will  be  heard  in  telephone  No.  i.  The  switch  mechanism  which 
comes  into  play  in  all  this  is  simple.  There  are  ten  rows  of 
switches,  ten  in  each  row :  the  lowest  row  runs  from  I  to  10,  the 
next  from  1 1  to  20,  and  so  on.  The  upward  motion  of  the  vertical 
rod  in  our  example  brought  it  to  the  fifties;  the  turning  motion 
decided  that  out  of  these  fifties  switch  58  should  be  connected 
with  No.  i.  When  a  conversation  ends,  hanging  up  the  receiver 
sends  a  current  over  both  wires  of  the  circuit  so  as  to  release  the 
selector  rod,  which  returns  to  its  original  position. 

If  instead  of  a  village  we  have  a  fairly  large  town,  with  an  ex- 
change of  looo  subscribers,  a  call  for  let  us  say  829  will  involve 
taking  to  the  stud  first  hole  8,  then  hole  2,  and  lastly  hole  9.  And 
so  on  for  exchanges  still  larger.  The  pioneer  inventor  in  auto- 
matic telephony  was  the  late  Mr.  Almon  B.  Strowger. 

From  triggers  electrical  we  now  pass  to  triggers  chemical.    A 
gun  may  be  charged  with  powder  and  remain  for  years  perfectly 
at  rest  until  a  touch  on  the  trigger  explodes  the 
powder  with  tremendous  effect.     The  example 
is  typical :  nature  and  art  abound  with  cases 
where  a  little  energy,  rightly  directed,  controls  energy  vastly,  per- 
haps infinitely,  greater  in  quantity.    Often  in  a  chemical  compound 
the  poise  of  attraction  is  so  delicate  that  it  may  be  disturbed  by  a 
breath,  or  by  a  note  from  a  fiddle,  as  when  either  of  these  induces 
iodide  of  nitrogen  to  explode.     A  beam  of  light  works  the  same 
result  with  a  mixture  of  chlorine  and  hydrogen.    One  of  the  most 


338  INITIATION 

familiar  facts  of  chemistry  is  that  a  fuel,  such  as  coal,  may  remain 
intact  in  air  for  ages.  Once  let  a  fragment  of  it  be  brought  to 
flaming  heat  and  all  the  rest  of  the  mass  will  take  fire  too.  Iron 
has  a  strong  affinity  for  oxygen,  but  for  union  there  must  be  at 
the  beginning  some  moisture  with  the  gas;  the  same  is  true  of 
carbon.  A  burning  jet  of  carbon  monoxide  may  be  extinguished 
by  plunging  it  into  a  jar  of  dried  oxygen.  Gases  from  the  throat 
of  a  blast  furnace,  at  a  temperature  of  250°  to  300°  Centigrade, 
are  not  inflammable  in  the  atmosphere  until  the  air  is  moistened  by 
steam  or  otherwise.  Then  in  a  flash  combustion  begins  in  earnest. 

In  photography  we  meet  with  similar  facts:  violet  rays  may 
begin  an  impression  which  yellow  light  can  finish  and  finish  only. 
Vulcanite  is  transparent  to  red  and  infra-red  rays  which,  although 
without  action  upon  an  unexposed  plate,  are  capable  of  continuing 
the  action  of  actinic  rays  upon  a  plate  which  has  been  exposed  for 
a  very  short  time. 

From  photography  let  us  pass  to  a  glance  at  the  atmospheric 

conditions  which  greatly  affect  its  work.    The  weather  from  day  to 

day  depends  upon  factors  so  variable  and  un- 

Why  Weather       stable  that  prediction  beyond  twenty- four  hours 

is  Uncertain.  is  unsafe.  "Suppose  a  stratum  of  air,"  says 
Professor  Balfour  Stewart,  "to  be  very  nearly 
saturated  with  aqueous  vapor;  that  is  to  say,  to  be  just  a  little 
above  the  dew-point ;  while  at  the  same  time  it  is  losing  heat  but 
slowly,  so  that  if  left  to  itself  it  would  be  a  long  time  before 
moisture  were  deposited.  Now  such  a  stratum  is  in  a  very  delicate 
state  of  molecular  equilibrium,  and  the  dropping  into  it  of  a  small 
crystal  of  snow  would  at  once  cause  a  remarkable  change.  The 
snow  would  cool  the  air  around  it,  and  thus  moisture  would  be 
deposited  around  the  snowflake  in  the  form  of  fine  mist  or  dew. 
Now,  this  deposited  mist  or  dew,  being  a  liquid,  and  giving  out  all 
the  rays  of  heat  possible  to  its  temperature,  would  send  its  heat 
into  empty  space  much  more  rapidly  than  the  saturated  air ;  there- 
fore it  would  become  colder  than  the  air  around  it.  Thus  more  air 
would  be  cooled,  and  more  mist  or  dew  deposited ;  and  so  on 
until  a  complete  change  of  condition  should  be  brought  about.  In 
this  imaginary  case  the  tiniest  possible  flake  of  snow  has  pulled 
the  trigger,  as  it  were,  and  made  the  gun  go  off,—  has  altered  com- 


WEATHER  PREDICTIONS  339 

pletely  the  whole  arrangement  that  might  have  gone  on  for  some 
time  longer  as  it  was,  had  it  not  been  for  the  advent  of  the  snow- 
flake.  We  thus  see  how  in  our  atmosphere  the  presence  of  a  con- 
densable liquid  adds  an  element  of  violence,  and  also  of  abruptness, 
amounting  to  incalculability,  to  the  motions  which  take  place. 
This  means  that  our  knowledge  of  meteorological  phenomena  can 
never  be  mathematically  complete,  like  our  knowledge  of  planetary 
motions,  inasmuch  as  there  exists  an  element  of  instability,  and 
therefore  of  incalculability,  in  virtue  of  which  a  very  considerable 
change  may  result  from  a  very  small  cause." 

In  view  of  the  inherent  difficulties  it  is  certainly  creditable  that 
the  predictions  of  the  United  States  Weather  Bureau  should  prove 
true  six  times  in  seven,  greatly  inuring  to  the  safety  of  mariners, 
of  passengers  by  lake  and  sea,  and  to  the  saving  of  crops  under 
threat  of  destruction  by  storms. 


CHAPTER  XXIII 
SIMPLIFICATION 

Simplicity  always  desirable,  except  when  it  costs  too  much  .  .  .  Taking 
direct  instead  of  roundabout  paths.  Omissions  may  be  gainful  .  .  . 
Classification  and  signaling  simpler  than  ever  before. 

FOR  a  simple  task  the  inventor's  means  should  be  as  simple  as 
possible.      Mr.    J.   J.    Thomas   in   his    "Farm    Implements" 
says  :— 

"After  a  trial  of  a  multitude  of  implements  and  machines,  we 
fall  back  on  those  of  the  most  simple  form,  other  things  being 
equal.  The  crow-bar  has  been  employed  from 
time  immemorial,  and  it  will  not  likely  go  out  simplicity  of 
of  use  in  our  day.  For  simplicity  nothing  ex-  Build  Desirable, 
ceeds  it.  Spades,  hoes,  forks  are  of  similar 
character.  The  plow,  though  made  up  of  parts,  becomes  a  single 
thing  when  all  are  bolted  and  screwed  together.  For  this  reason, 
with  its  moderate  weight,  it  moves  through  the  soil  with  little  diffi- 
culty—turning aside  for  obstructions,  on  account  of  its  wedge 
form,  when  it  cannot. remove  them.  The  harrow,  although  com- 
posed of  many  pieces,  becomes  a  fixed,  solid  frame,  moving  on 
through  the  soil  as  a  single  piece.  So  with  simpler  cultivators. 
Contrast  these  with  Pratt's  ditching  machine  considerably  used 
some  years  ago,  but  ending  in  failure.  It  was  ingeniously  con- 
structed and  well  made,  and  when  new  and  every  part  uninjured, 
worked  admirably  in  some  soils.  But  it  was  made  up  of  many 
parts  and  weighed  nearly  half  a  ton.  These  two  facts  fixed  its 
doom.  A  complex  machine  of  this  weight  moving  three  to  five 
feet  per  second,  could  not  strike  a  large  stone  without  a  formidable 
jar,  and  continued  repetitions  of  such  blows  bent  and  deranged 
the  working  parts.  After  using  a  while,  these  bent  portions  re- 
tarded its  working;  it  must  be  frequently  stopped,  the  horses  be- 

340 


ECONOMY  THE  SOLE  AIM  341 

coming  badly  fatigued,  and  all  the  machines  were  finally  thrown 
aside.  This  is  a  single  example  of  what  must  always  occur  with 
the  use  of  heavy  complex  machinery  working  in  the  soil.  Mowing 
and  reaping  machines  may  seem  to  be  exceptions.  But  they  do 
not  work  in  the  soil,  or  among  stones ;  but  operate  on  the  soft, 
slightly  resisting  stems  of  plants.  Every  farmer  knows  what  be- 
comes of  them  when  they  are  repeatedly  driven  against  obstruc- 
tions by  careless  teamsters." 

In  discussing  form  we  saw  that  simple  shapes,  such  as  those  of 
sticks  cut  from  a  cylindrical  tree,  are  not  so  strong  as  the  less 
simple  forms  of  hollow  cylinders.     We  found 
that  a  joist,  of  plain  rectangular  section,  is  not       simplification 
so  good  a  burdenbearer  as  a  girder  whose  sec-         Has  Limits, 
tion  resembles  the  letter  I.     If  a  slide  for  a 
timber  is  to  be  built  on  a  mountain  side,  a  novice  would  suppose 
that  a  straight  inclined  plane  would  afford  the  speediest  path  for 
the  descending  wood.    Not  so.    More  speedy  is  a  slide  contoured 
as  a  cycloid,  the  curve  traced  by  a  pencil  fastened  to  the  rim  of  a 
wheel  as  the  wheel  rolls  along  a  floor  beside  a  wall  against  which 
the  pencil  presses. 

Not  all  tasks  are  simple,  so  that  it  is  often  best  to  build  and  use 
a  machine  as  complicated  as  a  turret-lathe  or  a  Jacquard  loom. 
Whatever  the  inventor  seeks  first,  last  and  all  the  time  is  Econ- 
omy; to  that  end  he  adopts  whatever  means  will  serve  him  best, 
whether  simple  or  not.  Professor  A.  B.  W.  Kennedy,  famous  as 
a  teacher  of  machine  design,  says : — 

"Simplicity  does  not  mean  fewness  of  parts.  Reuleaux  showed 
long  ago  that  with  machines  there  was  in  every  case  a  practical 
minimum  number  of  parts,  any  reduction  below  which  was  accom- 
panied by  serious  practical  drawbacks.  Nor  is  real  simplicity  in- 
compatible with  considerable  apparent  complexity.  The  purposes 
of  machines  being  continually  more  complex,  simplicity  must  not 
be  looked  upon  as  absolute,  but  only  in  its  relation  to  a  particular 
purpose.  There  are  many  very  complex-looking  pieces  of  ap- 
paratus which  work  so  directly  along  each  of  their  main  branch 
lines  that  they  are  in  reality  simple.  It  is  usual  that  the  first 
attempt  to  carry  out  a  new  purpose  results  in  a  very  complicated 
machine.  It  is  only  by  the  closest  examination  of  the  problem,  the 


342  SIMPLIFICATION 

getting  at  its  very  essence,  that  the  machine  can  be  simplified. 
If  a  problem  is  only  soluble  by  extremely  complicated  apparatus, 
it  becomes  a  question  whether  it  is  worth  having.  Closely  allied 
to  simplicity  is  Directness.  Certain  transformations  are  unavoid- 
able, but  the  fewer  the  better.  In  some  cases  they  may  be  as  in- 
dispensable as  the  abused  middleman  in  matters  economic.  In  the 
first  machine  to  do  something  mechanically  hitherto  done  by 
hand,  the  error  is  often  made  of  trying  to  imitate  hand-work 
rigorously.  The  first  sewing-machine  was,  I  believe,  made  to 
stitch  in  the  same  way  as  a  seamstress.  It  was  not  until  a  form 
of  stitch  suitable  for  a  machine,  although  unsuitable  for  the  hand, 
was  devised,  that  the  sewing-machine  was  successful.  The  first 
railroad  carriages  were  practically  stage-coaches  put  on  trucks, 
from  which  the  present  carriages  have  only  very  slowly  been 
evolved." 

A  few  years  ago  it  was  usual  to  attach  pumps,  dynamos,  and 
other  machinery  to  their  actuating  engines  by  pulleys  an~l  belts. 
To-day  in  most  cases  the  connection  is  direct; 
Directness.          all  the  energy  which  would  be  absorbed  by  inter- 
vening wheels  and  leather  is  saved.    In  steam- 
turbines  one  and  the  same  shaft  carries  the  steam- vanes  and  the 
armature  of  an  electrical  generator.     Li  saw-mills  of  modern  de- 
sign a  very  long  steam  cylinder  is  provided  with  a  piston  directly 
attached  to  the  saw  carriage.     The  same  principle  gives  high 
economy  to  the  steam  hammer  and  pile-driver  of  Nasmyth.    Ham- 
mers, drills,  cutters  and  other  tools  driven  by  compressed  air  are 
directly  attached  to  the  rod  which  holds  the  piston.    In  like  man- 
ner Saunders'  channeling  machine,  actuated  by  steam,  has  its  cut- 
ters attached  to  its  piston,  so  that  a  blow  is  dealt  with  no  inter- 
vening crank-shaft,  lever  or  spring. 

Direct,  too,  is  the  binding  machine  for  magazines  and  cheap 
books,  which  simply  stitches  with  wire  the  whole  together  at  the 
back,  as  if  so  many  thicknesses  of  cloth.  With  the  same  imme- 
diacy we  have  wall-papers  printed  directly  from  the  oak  or  maple 
they  are  to  represent.  Indeed,  veneers  are  now  so  cheap  and  good 
as  to  be  used  instead  of  paper  as  wall  coverings.  In  the  province 
of  art  Mr.  Hubert  Herkomer  has  accomplished  a  notable  feat  in 
the  way  of  directness,  dispensing  with  the  camera,  or  any  of  the 


PAYING  TWO  DEBTS  AT  ONCE         343 

etcher's  preliminaries  of  biting  or  rocking.  He  paints  in  mono- 
chrome on  a  copper  plate  as  he  would  on  a  panel  or  canvas,  covers 
his  painting  with  fine  bronze  powder  to  harden  the  surface,  from 
which  he  then  takes  an  electrotype. 

A  supreme  feat  of  directness  was  the  invention  of  a  machine 
which  relates  itself  to  art,  science  and  business,  the  phonograph. 
Forty  years  ago  Faber  constructed  a  talking  machine  of  bellows 
to  imitate  the  lungs,  with  an  artificial  throat,  larynx,  and  lips 
affording  a  weird  and  faulty  imitation  of  the  voice.  Edison,  bid- 
ding sound-waves  impress  themselves  directly  on  a  plastic  cyl- 
inder, reproduces  human  tones  and  other  sounds  with  vastly  better 
effect.  Faber  sought  to  copy  the  method  of  voice  production. 
Edison  set  himself  the  task  of  taking  tones  as  produced  and 
making  them  impress  a  surface  from  which  they  can  be  repeated 
at  will. 

A  lamp  commonly  used  by  camping  parties,  and  well  worthy 
of  wider  employment,  is  at  once  a  source  of  heat  and  light  ;  while 
it  boils  a  kettle  it  sheds  an  ample  beam  upon 
one's  table  or  book.     Just  this  union  of  two        Contrivances 


services  may  be  found  in  the  crude  lamp  of        _    ^, 

Double  Debt. 
the  Eskimo. 

Many  processes  of  manufacture  once  separate  are  now  united 
with  economy  of  time  and  power.  Steam  cylinders  for  mangling, 
ironing  and  surfacing  paper,  effect  smoothing  and  drying  at  one 
operation.  Green  lumber  for  making  furniture  is  bent  and  sea- 
soned at  the  same  time.  Wire  is  tempered  as  drawn.  At  first 
reflectors  were  distinct  from  lamps  ;  in  an  excellent  form  of  in- 
candescent bulb  the  upper  part  of  the  container  is  silvered,  in- 
creasing the  efficiency  of  reflection  in  decided  measure,  as  shown 
on  page  75. 

Sometimes  an  indirect  path  is  better  than  a  direct  course;  or, 
as  the  sailors  say:  "The  longest  way  round  is  the  shortest  way 
there."  We  can  readily  measure  the  contents 
of  solids  which  are  regular  or  fairly  regular  of 
outline.  It  is  easy  to  compute  or  estimate  the 
contents  of  a  stone  as  hewn  by  a  mason  to  form  part  of  a  wall,  but 
to  find  the  volume  of  a  rough  boulder  by  direct  measurement  is  too 
difficult  a  task  to  be  worth  while.  Let  us  have  recourse,  then,  to 


344  SIMPLIFICATION 

an  indirect  plan  which  goes  back  to  Archimedes :  it  will  remind  us 
of  how  the  casting  process  evades  the  toil  of  chipping  or  ham- 
mering a  mass  of  metal  into  a  desired  form.  We  take  a  vessel 
of  regular  shape,  preferably  a  cylinder,  duly  graduated,  and 
partly  fill  it  with  water.  Any  solid,  however  irregular,  immersed 
therein,  will  at  once  have  its  contents  declared  by  the  height  to 
which  the  water  rises  in  its  container,  the  water-levels  before  and 
after  the  immersion  being  compared.  Incidentally  we  here  have 
a  means  of  ascertaining  specific  gravities.  Weigh  this  body  be- 
fore and  during  immersion ;  comparison  of  the  two  quantities  will 
tell  the  specific  gravity  of  the  body,  that  is  its  density  as  compared 
with  that  of  water.  For  example  a  mass  of  iron  which  in  air 
weighs  7.75  pounds  will  in  water  weigh  6.75  pounds,  so  that  the 
specific  gravity  of  iron  is  7.75,  the  difference  between  the  two 
weights  being  unity. 

Sometimes  we  wish  to  know  the  solid  contents  of  a  body  which 
will  not  bear  immersion  in  water;  a  mass  of  gum,  for  instance. 
In  such  a  case  we  immerse  the  body  in  a  graduated  vessel  filled 
with  fine  dry  sand,  carefully  sifted  free  of  hollow  spaces.  Both 
before  and  after  immersion  the  sand  is  brought  to  a  level  which 
is  carefully  noted.  The  difference  between  these  levels,  measured 
in  the  graduations  of  the  container,  gives  the  solid  contents  of 
the  immersed  body. 

The  degree  in  which  a  crystal,  or  a  particular  kind  of  glass, 
bends  a  beam  of  light  is  usually  measured  by  giving  the  crystal  or 

glass  the  form  of  a  prism,  through  which  rays 
Measuring  c  .  J 

Refraction  are  sent>     Sometimes  a  crystal  is  so  small  and 

irregular  that  this  method  is  not  feasible.  Then 
the  inquirer  resorts  to  an  indirect  plan.  He  immerses  the  crystal 
in  liquids  which  he  mixes  until  the  crystal  disappears  through 
ceasing  to  bend  light  differently  from  the  surrounding  bath.  He 
then  fills  a  hollow  glass  prism  with  this  liquid,  and  in  noting  its 
refraction  he  learns  that  of  the  immersed  crystal. 

A  fresh  eye,  with  a  keen  brain  behind  it,  often  detects  wasted 
work  in  a  process  long  sanctioned  by  tradition.  At  the  Tamarac 
Copper  Mine,  in  Northern  Michigan,  some  new  ore-crushers  were 
needed  in  1891.  Among  the  engineers  who  sought  to  furnish 
these  machines  was  Mr,  Edwin  Reynolds,  of  Milwaukee,  whose 


GAIN  IN  OMISSION 


345 


improvements  of  the  Corliss  engine  have  made  him  famous.    That 

he  might  see  ore-crushers  at  work  for  the  first  time  in  his  life,  he 

visited  the  Tamarac  mine.     He  observed  that 

the  stamps  were  built  on  an  immense  bed  of        Omission  of 

costly  timbers  and  rubber  sheets,  supposed  to 

be  indispensable  to  efficiency.  His  eye,  unwarpcd 

by  harmful  familiarity,  utterly  condemned  this  elastic  foundation. 

He  at  'once  proposed  to  discard  both  timbers  and  rubber,  and  rear 


Needless 
Elements. 


Blenkinsop's  locomotive,  1811. 
Middleton  Colliery,  near  Leeds,  England. 

new  crushers  directly  on  a  vast  block  of  solid  iron.  This  heresy 
quite  shocked  the  directors  of  the  Tamarac  Company ;  they  stood 
out  against  Mr.  Reynolds'  plan  for  two  years.  Then,  with  pro- 
found misgivings,  they  allowed  him  to  erect  a  stamp  of  the 
cheap  and  simple  pattern  he  had  suggested,  so  laying  the  iron  bed 


346  SIMPLIFICATION 

that,  in  case  of  its  expected  failure,  work  would  be  delayed  not 
more  than  two  days.  Up  went  the  Reynolds'  stamp,  and  out 
poured  sixty  per  cent,  more  crushed  ore  than  from  a  preceding 
machine  using  the  same  power.  Instant  by  instant  its  energy  was 
wholly  exerted  in  crushing  rock,  not  largely  in  the  useless  com- 
pression of  an  enormous  elastic  bed. 

Long  before  there  was  any  Tamarac  Mine,  inventors  had  both- 
ered themselves  providing  for  difficulties  as  imaginary  as  those 
which,  at  vast  outlay,  were  met  by  the  timber  underpinning  of 
old-time  ore  stamps.  In  1825  the  builders  of  locomotives  at 
Easton,  in  England,  provided  their  engine-wheels  with  teeth  which 
worked  into  racks  with  corresponding  projections.  They  were 
afraid  that  a  smooth  wheel  on  a  smooth  track  would  slip  without 
onward  motion.  Their  unnecessary  gear  was  discarded  when  it 
was  found  that  under  a  heavy  engine  a  smooth  wheel  has  adequate 
adhesion  on  a  rail  as  smooth  as  itself.  Toothed  wheels  and  racks 
are  now  only  at  work  on  the  railroads  of  Mount  Washington  and 
other  steep  acclivities.  As  James  Watt  used  to  say  to  William 
Murdock,  his  trusted  lieutenant,  — "It  is  a  great  thing  to  know 
what  to  do  without.  We  must  have  a  book  of  blots—things  to 
be  scratched  out." 

Daily  newspapers  in  part  owe  their  cheapness  to  an  omission 
that  at  first  seemed  bold  enough.  For  many  years  printing  paper, 

made  in  continuous   rolls   each   of   a  mile   or 

Printers  Abandon     more,  used  to  be  cut  into  sheets,  fed  one  by  one 

Useless  Work.       to  the  press.     It  was  a  long  stride  in  economy 

when  the  printer  left  the  roll  alone,  and  let  an 
automatic  press  feed  itself  from  the  unwinding  paper,  cutting  off 
a  sheet  only  after  the  printing^ 

A  parallel  example  is  recorded  in  the  twin  art  of  telegraphy. 
At  first  it  was  believed  that  two  wires  were  indispensable  for  a 

circuit.     Steinheil  showed  that  a  single  wire 

Electricity  Used      suffices  if  its  terminals  are  soldered  into  plates 

as  Produced.        buried  in  the  ground.     Thus,  at  a  stroke,  by 

impressing  the  earth  into  the  service  of  elec- 
trical communication,  he  reduced  the  cost  of  telegraphic  lines  by 
one  half.  In  another  field  the  electrician  has  given  himself  a 
good  deal  of  trouble  in  vain.  As  it  originally  streamed  from 


ELECTRICITY  USED  AS  PRODUCED  347 

voltaic  batteries,  the  electric  current  had  always  a  single  direction; 
it  was,  to  use  a  familiar  phrase,  a  direct  current.  But  when  Far- 
aday invented  the  first  dynamo,  and  produced  electricity  from 
mechanical  motion  instead  of  from  more  costly  chemical  energy, 
the  current  was  not  direct  but  alternating ;  that  is,  its  pulses  came 
at  one  instant  from  the  positive  pole,  the  next  instant  from  the 
negative.  Inventors  took  great  pains  in  devising  apparatus  to 
convert  these  alternating  pulses  into  a  direct  current  such  as  that 
yielded  by  a  voltaic  battery.  To-day  the  alternating  current  for 
many  important  purposes,  including  transportation,  is  employed 
just  as  it  leaves  the  dynamo.  Such  a  current  usually  has  com- 
paratively high  tension,  at  which  transmission  is  much  more 
economical  than  at  low  tension,  small  conductors  serving  instead 
of  large  ones.  This  advantage  in  many  cases  more  than  offsets 
the  loss  entailed  by  reversal  of  the  magnetic  field  at  each  alterna- 
tion; a  loss  but  small  when  iron  for  the  electro-magnets  is  well 
chosen. 

Roc1:  may  be  so  hard  as  to  withstand  a  drill  of  the  hardest 
steel ;  then  the  engineer  pours  an  acid  of  the  necessary  dissolving 
power.     A  water  pipe  may  freeze  at  a  point 
difficult  of  access ;  it  is  thawed  by  the  warmth        short  Cuts  in 
created  by  an  electric  current.    A  surveyor  has        Engineering, 
to  reduce  to  square  feet  the  irregular  area  of  a 
factory  site  or  a  garden  plot ;  around  the  edge  of  his  diagram  he 
runs  a  planimeter,  it  tells  him  automatically  what  surface  it  has 
surrounded  in  its  excursion.     If  he  has  no  planimeter,  a  delicate 
balance  will  serve  just  as  well.     Let  him  take  a  piece  of  paper, 
uniform  in  thickness,  and  cut  it  into  the  shape  of  the  area  in 
question.    In  weighing  the  diagram  with  care  he  learns  its  super- 
ficies because  he  knows  the  weight  of  each  square  inch  or  foot  of 
the  paper.     Pumps  for  ages  have  exercised  the  wit  of  inventors 
who  have  devised  wheels,  screws,  pistons,  and  scoops  of  every 
imaginable  form.     M.  Giffard  boldly  discarded  all  moving  parts 
whatever  and  in  his  injector,  actuated  directly  by  a  blast  of  steam, 
provided  a  capital  means  of  sending  water  into  a  boiler. 

A  generation  ago  engineers  of  eminence  were  attempting  the 
transmission  of  energy  in  a  variety  of  ways.  Ropes  and  wire 
cables  were  installed  for  considerable  distances  in  Germany  and 


348  SIMPLIFICATION 

Switzerland;  in  France  there  was  an  extensive  piping  of  com- 
pressed air,  still  in  evidence  at  the  capital ;  and  water  under  high 
pressure  is  to  some  extent  to-day  employed  in  London.    All  these 
schemes,  together  with  the  old  methods  within  a  shop  itself  of 
taking  motion  from  motor  to  machine  by  belt  or  chain,  have  been 
wiped  off  the  slate  by  the  electrical  engineer.    With  a  tax  of  the 
lightest  he  carries  for  many  miles  in  a  slender  wire  a  current 
whose  energy  takes  any  form  we  please,— not  only  mechanical 
motion,  but  chemical  action,  light  or  heat.    Can  simplification  go 
farther  than  this,  or  the  future  hold  for  us  another  gift  as  golden? 
Binders,  reapers,  and  mowers  have  irregular  surfaces  which  it 
would  be  costly  to  paint  by  hand.    Even  to  use  the  painting  ma- 
chine which  works  by  compressed  air  would 
Printing  by         be  somewhat  expensive.     In  the  painting  shop 
Immersion.          of  a  factory  both  brushes  and  nozzles  are  ban- 
ished.   The  large  floor  is  fitted  up  with  a  series 
of  tanks :  overhead  are  the  lines  of  a  suspension  railway.     The 
tanks  are  filled  with  paint,  the  articles  to  be  treated  are  run  in  on 
the  rails,  lowered  automatically  for  their  bath,  and  then  carried 
off  to  drip  and  to  dry.    In  this  way  a  large  and  complicated  agri- 
cultural machine  can  be  painted  in  a  few  seconds.     Were  deep 
tanks  employed,  this  method  would  squeeze  oil,  varnish,  or  paint 
into  the  pores  of  wood  very  thoroughly. 

Astronomers  suffer  much  from  the  inaccuracy  of  the  images 
viewed  in  their  telescopes  in  consequence  of  the  disturbances  in 
the  atmosphere,  common  even  in  clear  weather. 
Churning  the  Air      Hence  observatories  have,  of  late  years,  been 
ln  a  TubeC°PiC       established  at  Arequipa,  Peru,  and  at  other  sta- 
tions where  the  atmosphere  is  calm  and  little 
disturbed  by  currents.     On  investigation  Professor  S.  P.  Lang- 
ley,  of  Washington,  discovered  that  a  good  deal  of  the  perturba- 
tion of  telescopic  images  arises  from  currents  within  the  tele- 
scopic tube  itself.    As  a  remedy  he  adopted  the  heroic,  yet  simple, 
measure  of  thoroughly  stirring  up  the  air  in  the  tube  by  a  blower 
or  other  suitable  means.     Its  air,  thus  brought  to  uniformity  of 
condition,  yielded  images  much  clearer  than  those  usually  ob- 
tained.    Especially  convincing  in  this  regard  are  capital  photo- 
graphs of  artificial  double  stars  whose  beams  were  entirelv  con- 


BINDING  OMITTED  849 

fined  within  a  horizontal  tube  in  which  they  traveled  to  and  fro 
through  no  less  than  140  feet  of  churned  air.  These  pictures 
showed  that  the  disturbance  within  the  tube  itself  appeared  to  be 
wholly  eliminated  by  the  device  of  vigorously  stirring  the  air 
column. 

This  recalls  a  method  of  shipping  pianos  in  refrigerator  cars. 
The  instruments  are  carefully  brought  to  the  temperature  of  the 
car,  which  is  maintained  at  about  zero,  Centigrade.  When  the 
pianos  arrive  at  their  destination  they  are  slowly  warmed  to  the 
temperature  of  common  air.  No  matter  how  long  they  have  been 
cold,  they  suffer  no  hurt ;  for  it  is  not  cold,  or  moderate  elevation 
of  temperature,  that  does  harm  so  much  as  uneasy  fluctuations 
from  one  to  the  other. 

When  one  visits  a  public  library,  the  title  of  a  particular  book 
is  found  in  the  catalogue  in  a  moment.  Every  book  as  acquired 
has  its  title  written  on  a  card,  and  thousands  of 
such  cards  are  placed  in  alphabetical  order,  just  Repiace  Books 
like  the  words  in  a  dictionary.  A  thousand 
cards  or  so  begin  with  "A,"  and  are  placed  in  a  drawer  marked 
"A,"  which  stands  first  in  the  case,  and  so  with  the  rest.  There 
is  always  room  to  spare  in  each  drawer,  so  that  when  a  card  for 
a  new  book  comes  in  there  is  space  for  it.  It  was  a  happy  thought 
of  a  Dutch  inventor  when  he  thus  made  an  index  which  can  al- 
ways K.  alphabetical,  easily  added  to  or  subtracted  from,  simply 
because  its  leaves  are  mere  cards  with  the  binding  of  a  common 
index  omitted.  In  public  libraries  the  catalogue-cards  are  of 
standard  sizes,  so  also  are  the  drawers  in  which  these  are  dis- 
posed. In  fact  library-furniture  of  all  kinds  is  to-day  thoroughly 
standardized  in  its  styles  and  dimensions,  making  it  easy  to  fit 
up  or  to  extend  a  library  whether  public  or  private. 

The  use  of  cards,  or  slips  for  like  purposes,  has  passed  from 
the  library  to  the  business  office,  the  study,  the  housekeeper's 
desk.  Merchants  keep  their  customers'  names  on  this  plan,  so  as 
to  send  them  price  lists  from  time  to  time.  Depositors  in  banks, 
policy-holders  in  assurance  companies,  tenants  of  real  estate  in 
cities,  members  of  clubs,  are  all  recorded  in  this  simple  and 
accessible  fashion.  Some  great  manufacturing  houses  re- 
ceive a  million  letters  in  a  twelvemonth;  an  adaptation  of  the 


350 


SIMPLIFICATION 


card-index  makes  any  single  letter  accessible  in  half  a  minute  at 
most.  To  an  extent  which  steadily  grows,  the  same  plan  is  ousting 
the  old-fashioned  ledgers  from  our  offices;  in  their  stead  we  are 
now  using  series  of  movable  leaves  which  are  removed  when 
rilled,  giving  place  to  new  leaves  in  an  unbroken  round. 

A  good  many  readers  make  notes  as  they  go.     If  these  are 
written  in  books  they  soon  become  so  numerous,  so  various  of 


Notes  on  loose  cards  in  alphabetical  order. 


topic,  as  to  demand  laborious  indexing.  It  is  better  to  take  the 
notes  in  a  form  which  will  index  itself.  Slips  of  good  paper  can 
be  bought  at  low  cost,  and,  as  in  the  accompanying  illustration, 
"Astronomy,"  "Glass,"  "Photography,"  or  other  headings  may  be 
adopted.  All  the  slips  under  a  given  head  are  numbered  con- 
secutively. Kept  on  edge  in  a  shallow  box,  or  tray,  they  are  self- 
indexing,  and  a  new  slip  takes  its  proper  place  at  once.  From  its 
compactness  this  kind  of  note-keeping  puts  a  premium  on  the 
abbreviations  which  suggest  themselves  in  a  special  study. 

A  card  system  employed  as  a  catalogue,  or  for  account  keeping, 

is  made  up  of  simple  units  which  may  be  added  to  or  deducted 

from  with  utmost  ease.     They  may  be  manip- 

Unit  Systems.        ulated  as  readily  as  the  bricks,  all  alike,  with 

which  a  child  builds  a  house,  a  box,  or  a  steeple. 

This  principle  a  few  years  ago  was  extended  to  book-cases,  each 


SECTIONAL  FURNITURE 


351 


about  a  foot  high  and  about  thirty-three  inches  long;  while  each 
formed  a  unit  by  itself  it  could  be  combined  with  other  such  units 
to  furnish  forth  a  library. 
This  plan  had  been  adopted 
for  office  furniture  of  all 
kinds,— cabinets  in  which 
papers  may  be  filed  away,  or 
which  are  divided  into 
pigeon-holes  for  blanks  and 
the  like.  In  some  handsome 
designs  a  unit  unfolds  as  a 
small  writing  desk,  while 
adjacent  units  contain  draw- 
ers of  various  sizes.  Each 
unit  is  so  moderate  in  di- 
mensions as  to  be  readily 
portable;  a  dozen,  a  score,  a 
hundred  may  be  joined  to- 
gether to  equip  a  sitting- 
room  or  the  cashier's  office 
in  a  bank. 

When  an  American  visits 
London  for  the  first  time,  he  Sectional  book-case,  desk, 

may  fall  into  an  error  which  and  drawers, 

will  much  provoke  him.  Sup- 
pose that  he  has  to  call  at  457  Strand.     He  begins  at  number  I 
in  that  thoroughfare,  and  proceeds  a  goodly  distance  when,  to  his 
dismay   he  observes   that   the   numbers   he   is 
passing  on  his  right  are  strictly  consecutive,—      Numbering  as  a 
loo,    101,    1 02  and   so  on.     A   weary  trudge 
brings  him  to  457,  opposite  number  I,  whence  he  started.     That 
odd  numbers  should  be  on  one  side  of  the  street,  and  even  num- 
bers on  the  other,  did  not  occur  to  the  city  fathers  of  London 
centuries  ago.    In  this  regard  a  forward  step  was  taken  in  Phila- 
delphia, where  the  streets  parallel  with  the  Delaware  River  are 
First,  Second,  and  so  on,  while  each  house  on  the  streets  crossing 
them  from  the  river  westward  is  so  numbered  as  to  tell  between 
what  streets  it  stands.    Thus,  when  we  walk  up  Chestnut  Street, 


352  SIMPLIFICATION 

the  first  door  above  Ninth  Street,  on  the  right,  is  901,  although 
the  house  next  below  it,  across  Ninth  Street,  is  839;  and  so  on 
with  all  parallel  streets.  If  the  thoroughfares  in  Philadelphia, 
running  at  right  angles  to  the  Delaware  River,  were  labeled  ave- 
nues, and  consecutively  numbered,  the  system  would  be  a  trouble- 
saver  indeed. 

In  New  York  the  cross  streets  as  they  run  east  or  west  of 
Fifth  Avenue  are  named  east  or  west.  In  crossing  each  avenue 
eastward  or  westward  the  numbers  jump  to  the  next  whole 
hundred,  as  in  Philadelphia.  The  building  at  the  southwestern 
corner  of  Third  Avenue  and  East  23rd  Street  is  162 ;  that  on  the 
eastward  corner,  opposite,  is  200.  Thus  in  cross  streets  the  num- 
ber of  a  house  tells  us  between  which  avenues  it  will  be  found. 

In  hotels  and  office-buildings,  throughout  America,  the  num- 
bering greatly  aids  an  inquirer.  Room  512,  for  example,  will  be 
found  on  the  fifth  floor;  immediately  beneath  is  412  on  the  fourth 
floor;  directly  above  is  612  on  the  sixth  floor,  the  first  figure  al- 
ways denoting  the  floor. 

A  capital  use  of  numerals  to  convey  information  is  that  devised 
by  Melvil  Dewey,  formerly  State  Librarian  of  New  York  at 
Albany.  He  divides  literature  into  ten  great 
Classifying  Books,  departments,  giving  each  of  them  one  of  the 
ten  numerals.  History,  in  this  scheme,  is  rep- 
resented by  9  as  the  first  figure  in  the  number  of  a  book ;  the  sec- 
ond figure  refers  to  the  geographical  division  to  which  the  work 
belongs,  thus  7  means  North  America;  the  third  figure  standing 
for  the  political  division  treated  by  the  book,  I  representing  the 
British  Empire.  A  work  on  Canadian  history,  therefore,  will  bear 
as  its  number,  971. 

Everybody  knows  what  a  money-saver  is  the  familiar  code  of  the 
ocean  cables,  by  which  "befogged"  stands  for  "Will  the  property 
be  advertised  for  sale?"  reducing  the  toll  by 
An  Advance  in  the  cost  of  sjx  words.  Most  of  the  terms  in  a 
CO(^e  are  not  dictionary  words,  but  such  colloca- 
tions of  letters  as  "carthurien"  and  "brank- 
strop."  A  new  code  devised  by  Mr.  Charles  G.  Burke,  of  New 
York,  proceeds  upon  the  use  of  four  numerals,  I,  2,  3,  4,  which 
he  transmits  in  the  fewest  signals  possible  to  a  cable,  I  is  a  dot ;  2 


BURKE  CODE 


358 


a  dash,  3  a  dash-dot ;  4  a  dot-dash.    This  is  how  they  look  when 
received  on  paper  in  comparison  with  ordinary  messages :— 


O  00  0000  00  OO  OOOO  O  O    O 

0000000000000000000090000000000000000000000000000 

000  0*00  00  000 


Ach        uchado 

Present  code.     Automatic  transmitting  strip. 


Achuch        ad 

Signals  received  from  above  strip. 


00  000  O 

000X3000000000  00<0.00  0*000*0 
00  000 


I     3    2  \  I   4   3    2 

Burke  code.  Transmitting  strip. 


I     3    2    I     I    4    3     Z 

Signals  received  from  above  strip. 


2    3 


The  Burke  numerals 
forming  the  permutations. 


422133     2 

A  Burke  combination  of  8. 


354  SIMPLIFICATION 

It  is  the  separate  signal  with  the  time  consumed  in  its  trans- 
mission which  is  the  real  unit  of  cost.  The  codes  now  in  use  em- 
ploy words  whose  letters,  as  signaled,  demand  more  than  twice 
the  time  required  by  the  Burke  system.  Thus  4221332,  as  trans- 
mitted by  Mr.  Burke,  means  "Advise  creditor  to  prove  claim  and 
accept  dividend,"  for  which  but  ten  signals  suffice.  .In  the  codes 
now  in  the  hands  of  the  public,  an  average  word  of  seven  letters 
would  contain  twenty-three  signals.  How  wide  is  the  variety  of 
sentences  possible  in  the  new  method?  If  the  numerals  are  em- 
ployed in  permutations  of  seven  figures,  as  1342423,  a  Burke  code 
'will  contain  16384  sentences ;  in  permutations  of  eight  figures, 
four-fold,  and  in  permutations  of  nine  figures,  sixteen-fold  as 
many,  or  262,144  sentences,  a  variety  much  more  ample  than  that 
of  any  other  system.  Mr.  Burke  finds  that  an  average  code  mes- 
sage has  8  letters  to  a  word,  each  word  requiring  about  25  elec- 
trical impulses  in  transmission;  an  average  permutation  on  his 
system  does  not  demand  more  than  10  impulses. 

Mr.  Burke  has  also!  devised  a  capital  mode  of  simplifying  tel- 
egraphic signals  of  all  kinds.  A  message  in  the  usual  Morse  code 
has  dots,  dashes  and  spaces,  each  produced  by  depressing  a  key 
for  a  short,  a  long,  or  a  longer  period.  Mr.  Burke  interrupts  a 
current  with  a  key  solely  with  dot-intervals ;  the  periods  during 
which  the  current  is  unbroken  are,  according  to  their  length,  dot- 
signals,  dash-signals,  or  spaces: — 


t       M      o        r 

Continental  Morse  Code. 


CHAPTER  XXIV 
THEORIES  HOW  REACHED  AND  USED 

Educated  guessing  .  .  .  Weaving  power  .  .  .  Imagination  indispensable 
.  .  .  The  proving  process  .  .  .  Theory  gainfully  directs  both  observation 
and  experiment  .  .  .  Professor  Tyndall's  views  .  .  .  Discursiveness  illus- 
trated in  Thomas  Young. 

A 5  far  back  as  the  first  man  with  brains  in  his  head,  there  was 
an  ache  to  know  why  the  sun  shone,  the  stars  twinkled,  the 
winds  blew,  why  harvests  here  were  plentiful  and  there  scant. 
The  whole  burden  of  witchcraft,  of  fetichism,  of  beliefs  in  voo- 
doo, is  a  pathetic  proof  of  this  human  longing 
to  explain.  What,  after  all,  are  superstitions  Theories  as 
but  premature  explanations  that  overstay  their  Finder  Thoughts, 
time?  When  men  of  thought  get  a  glimpse  of 
an  interpretation  really  true,  they  are  eager  to  prolong  that 
glimpse  until  it  becomes  a  survey  whose  due  tests  confirm  and 
buttress  a  well  grounded  anticipation.  This  exploring  process 
reminds  us  of  what  took  place  long  ago  when  an  architect  of  un- 
exampled boldness  first  imagined  a  dome  for  a  temple,  and 
brought  his  dream  to  fulfilment.  He  began  by  rearing  a  single 
arch,  fairly  strong,  yet  hardly  strong  enough ;  a  second  arch  arose 
to  meet  the  first  at  their  common  crest;  now,  in  mutual  support 
both  had  a  stability  neither  could  display  alone ;  at  last  when  the 
wall  had  gone  full  circle  it  had  a  strength  vastly  greater  than 
that  of  any  part  by  itself.  The  long-admired  arch  had  indeed 
become  no  more  than  an  element  to  be  joined  with  other  arches  to 
create  a  unit  of  an  order  distinctly  higher. 

For  ages  the  men  who  studied  nature  looked  upon  it  as  little 
changed  since  it  left  its  Maker's  hand.  Of  infinite  stimulus  was 
the  perception  that  it  is  a  drama,  not  a  tableau,  which  spreads  it- 
self before  the  eye.  Speedily  and  with  incomparable  instruction 

355 


356  THEORIES 

it  was  traced  how  every  actor  in  that  drama  had  been  molded 
by  the  part  it  had  played  in  maintaining  itself  upon  the  stage  of 
life.  Every  rival,  parasite  or  foe,  every  stress  of  climate,  was 
studied  in  its  influence  on  food  or  frame,  while  the  ever-threat- 
ened doom  for  irresponsiveness  was  the  extinction  which  befell 
countless  forms  once  masters  of  the  earth.  No  hue  of  scale  or 
feather,  no  barb  or  tusk,  no  curve  of  beak  or  note  of  song  but 
served  a  purpose  in  the  plot  or  advanced  the  action  in  scene  con- 
flict to  the  death.  When  Darwin  was  confronted  in  plant  or  beast 
by  an  organ  or  a  habit  which  puzzled  him,  he  was  wont  to  ask, 
What  use  can  this  have  had  ?  And  seldom  was  the  question  asked 
in  vain.  He  laid  great  stress  on  the  directive  worth  of  a  well- 
considered  theory.  He  tells  us,  "I  am  a  firm  believer  that  without 
speculation  there  is  no  good  and  original  observation/'  In  a  letter 
he  remarks,  "It  is  an  old  and  firm  Conviction  of  mine  that  the 
naturalists  who  accumulate  facts  and  make  many  partial  general- 
izations are  the  real  benefactors  of  science.  Those  who  merely 
accumulate  facts  I  cannot  very  much  respect/' 

In  rising  from  facts  to  explanations  a  weighty  debt  is  due  to 
modern  aids  to  eyes  and  hands.  To  men  who  knew  only  what 
direct  vision  could  tell  them  in  a  single  life-time,  it  was  but  na- 
tural to  repeat : — "The  thing  that  hath  been,  is  that  which  shall  be ; 
and  that  which  is  done,  is  that  which  shall  be  done ;  and  there  is 
no  new  thing  under  the  sun."  But  we  of  to-day  are  in  different 
case.  The  astronomer,  joining  camera  to  telescope,  lengthens  the 
diameter  of  the  known  universe  a  thousand- fold ;  he  discovers 
system  after  system  in  stages  of  life  such  as  our  sun  and  its  at- 
tendant orbs  have  passed  through  in  ages  so  remote  as  to  refuse 
computation.  And  many  types  of  nebulae  and  stars  are  now 
studied  which  were  never  so  much  as  imagined  until  they  re- 
vealed themselves  upon  the  photographic  plate.  Meanwhile  the 
geologist,  examining  the  closely  welded  ribs  of  our  globe,  com- 
paring the  birds,  beasts  and  men  of  to-day  with  their  earliest 
known  ancestry,  believes  that  the  earth  has  been  a  scene  of  life  for 
a  million  centuries  or  more.  As  we  restore  one  act  after  another 
in  this  great  cosmical  drama,  we  are  able  to  forecast  those  which 
may  next  appear.  Because  the  whole  scheme  of  things  from 
centre  to  rim  pulses  in  one  ethereal  ocean,  every  actor  has  inter- 


WHAT  IS  MATTER?  357 

play  with  every  other,  so  that  the  sweep  of  events  discloses  a  unity 
all  the  more  intimate  the  more  closely  it  is  studied.  At  this  hour 
physicists  and  chemists,  with  electricity  their  new  servant  at  com- 
mand, are  gathering  proof  that  what  have  long  been  called  "ele- 
ments," are  probably  one  substance,  variously  assembled,  moving 
at  speeds  and  in  paths  infinitely  diverse,  repeating  in  little  the 
mighty  swings  of  suns  and  planets.  Throughout  these  researches 
a  constant  spur  is  the  thought  that  here  may  be  traced  such  pro- 
cesses of  development  as  have  been  laid  bare  in  every  other  pro- 
vince of  nature.  From  circumference  to  centre,  evolution  is  the 
master  key  of  each  keen  questioner. 

Organic  nature  to  the  modern  interpreter  is  thus  alive  through 
and  through..  In  his  view  atom  and;  molecule  are  also  alive  in  a 
subordinate,  elemental  degree.  Indeed,  he 
thinks,  it  is  their  life  borne  in  air,  water  and  Modern  Views 
food  which  in  plant  or  animal  rises  to  new 
planes  of  dignity.  He  looks  afresh  at  the  broken  alum  crystal 
which  repairs  itself  in  a  solution,  and  sees  there  the  removal  of  the 
imaginary  fence  which  long  divided  organic  nature  from  in- 
organic. (See  illustration,  page  194.)  It  was  a  shrewd  guess  of 
Sir  Isaac  Newton  that  the  diamond  is  combustible ;  he  did  not 
suspect  it  to  be  carbon,  but  he  knew  it  to  be  highly  refrangible  as 
are  many  combustible  bodies.  His  conjecture  shows  him  taking 
the  first  step  toward  the  current  view  that  properties,  the  modes 
of  behavior  of  matter,  are*  not  passive  qualities,  but  are  due  to 
real  activities;  that  what  a  substance  is  depends  upon  how  its 
ultimate  parts  mave.  Clausius  and  Maxwell  in  a  theory  which 
marks  a  new  era  explained  the  elasticity  of  gases  as  manifested  in 
the  ceaseless  motion  of  their  molecules,  declaring  that  an  ounce  of 
air  within  a  fragile  jar  is'able  to  sustain  the  pressure  of  the  atmos- 
phere around  it,  because  the  air,  though  only  an  ounce  in  weight, 
clashes  against  its  container  with  a;n  impact  forcible  enough  to 
balance  the  external  pressure.  Proof  whereof  appears  in  measur- 
ing the  velocity  of  air  as  it  rushes  into  a  vacuum.  Here  a 
significant  point  is  that  in  leaving  the  realm  o-f  mass-mechanics, 
where  the  tax  of  friction  is  inexorable,  we  enter  a  sphere  where 
the  swiftest  motion  may  go  on  forever  without  paying  friction 
the  smallest  levy. 


358  THEORIES 

Elasticity  of  solids  is  explained  on  the  same  principle.     If  we 

swiftly  turn  a  gyroscopic  wheel  we  can  only  change  its  plane  of 

rotation  by  an   effort,   which   effort   is   repaid 

Elasticity  when  the  n\etal  is  allowed  to  resume  its  original 

plane  of  motion.     It  is  imagined  that  in  like 

manner  the  particles'  in  an  elastic  spring  move  rapidly  in  a  definite 

plane ;  if  deflected  therefrom-  they  oppose  resistance  and  are  ready 

to  do  work  in  returning  thereto.    Of  kindred  to  the  kinetic  theory 

of  elasticity  is  the  explanation  of  heat  a,s  a  distinct  and  ceaseless 

molecular  motion,  on  which  the  dimensions  of  masses  depend.   It 

has  long  seem.ed  to  me  that  every  case  of  "potential"  energy,  as 

that  of  a  spring  bent  or  coiled,  may  in  like  manner  embody  actual 

though  impalpable  and  invisible  motion.    I  presented  this  view  in 

the.  Popular  Science  Monthly,  December,  1876. 

The  ve.ry  constitution  of  matter  is  now  referred  to  the  motions, 
highly  diversified,  of  the  simplest  substance  possible.  Helm- 
holtz,  Lord  Kelvin,  and  Professor  Clerk  Maxwell  have  imagined 
the  molecules  of  lead,  iron,  or  other  element  as  vortices  born  of 
the  ether  in  which  without  resistance  they  forever  whirl.  As  we 
see  in  the  case  of  a  quickly  rotated  chain,  substantial  rigidity  is 
conferred  by  motion  sufficiently  swift.  Nor  are  molecules  with- 
out somewhat  of  individuality.  We  are  wont  to  think  of  masses 
of  solid  iron  as  precisely  similar  in  quality,  but  experience  shows 
us  that  one  bar  of  iron  may  vary  from  another  by  all  that  has 
differenced  the  history  of  the  two.  A  careful  workman  uses 
a  steel  die  for  only  a  short  service  before  he  returns  it  to  the  an- 
nealer,  well  assured  that  the  metal,  despite  its  seeming  wholeness, 
has  suffered  severe  internal  strain  at  every  blow,  which,  were  no 
caution  exercised,  would  soon  reveal  itself  in  fracture  of  the  die, 
or  ruined  work.  Facts  of  this  kind,  which  every  day  confront 
the  mechanic  and  engineer,  convey  a  prophecy  of  the  sensibility 
and  memory  which  dawn  with  life. 

A  theory  helpful  to  the  observer  or  the  experimenter  comes  at 

last,  in  many  cases,  from  much  guessing.     The  theorist  fills  his 

mind  with  facts,  broods  over  them,  endeavors 

Guesses  and         to  expiam  them,  but  whether  his  theory  is  true 

or  false  must  be  decided  solely  by  proof.  This 

point  was  clearly  stated  by  Dr.  Pye-Smith,  of  London,  in  his 


UNIFICATION  359 

Harvcian  oration,  1893 :— "As  Paley  justly  puts  it,  he  only  dis- 
covers who  proves.  To  hit  upon  a  true  conjecture  here  and  there, 
amid  a  crowd  of  untrue,  and  leave  it  again  without  appreciation 
of  its  importance,  is  a  sign,  not  of  intelligence,  but  of  frivolity. 
We  are  told  that  of  the  seven  wise  men  of  Greece,  one  (I  believe 
it  was  Thales)  taught  that  the  sun  did  not  go  around  the  earth, 
but  the  earth  around  the  sun/  Hence  it  has  been  said  that 
Thales  anticipated  Copernicus— a  flagrant  example  of  the  fallacy 
in  question.  A  crowd  of  idle  philosophers  who  sat  through  the 
long  summer  days  and  nights  of  Attica  discussing  all  things  in 
heaven  and  earth  must  sometimes  have  hit  upon  a  true  opinion, 
if  only  by  accident,  but  Thales,  or  whoever  broached  the  helio- 
centric dogma,  had  no  reason  for  his  belief  and  showed  himself 
not  more,  but  less,  reasonable  than  his  companions.  The  crude 
theories  and  gross  absurdities  of  phrenology  are  not  in  the  least 
justified  or  even  excused  by  the  present  knowledge  of  cerebral 
localization ;  nor  do  the  baseless  speculations  of  Lamarck  and 
Erasmus  Darwin  entitle  them  to  be  regarded  as  the  forerunners 
of  Charles  Darwin.  Up  to  1859  impartial  and  competent  men 
were  bound  to  disbelieve  in  evolution.  After  that  date,  or  at 
least,  so  soon  as  the  facts  and  arguments  of  Darwin  and  Wallace 
had  been  published,  they  were  equally  bound  to  believe  in  it.  He 
discovers  who  proves,  and  by  this  test  Harvey  is  the  sole  and 
absolute  discoverer  of  the  movements  of  the  heart  and  of  the 
blood." 

Discovery  is  the  reward  of  diligence,  such  as  that  of  Harvey, 
but  not  of  diligence  alone.  Professor  William  James,  in  his 
Psychology  remarks :— "The  inquirer  starts 
with  a  fact  of  which  he  sees  the  reason,  or  a 
theory  of  which  he  sees  the  proof.  In  either 
case  he  keeps  turning  the  matter  incessantly  in  his  mind,  until 
by  the  arousal  of  associate  upon  associate,  some  habitual,  some 
similar,  one  arises  which  he  recognizes  to  suit  his  need.  This, 
however,  may  take  years.  No  rules  can  be  given  by  which  the 
investigator  can  proceed  straight  to  his  result ;  but  both  here  and 
in  the  case  of  reminiscence  the  accumulation  of  helps  in  the  way 
of  associations  may  advance  more  rapidly  by  the  use  of  certain 
methods.  In  striving  to  recall  a  thought,  for  example,  we  may 


360  THEORIES 

of  set  purpose  run  through  the  successive  classes  of  circum- 
stances with  which  it  may  possibly  have  been  connected,  trusting 
that  when  the  right  member  of  the  class  has  turned  up  it  will 
help  the  thought's  revival.  ...  In  scientific  research  this  ac- 
cumulation of  associates  has  been  methodized  by  Mill  as  'four 
methods  of  experimental  inquiry/  By  the  method  of  Agree- 
ment, of  Difference,  of  Residues,  and  of  Concomitant  Variations, 
we  make  certain  lists  of  cases,  and  by  ruminating  these  lists  in 
our  minds  the  cause  we  seek  will  be  more  likely  to  emerge.  But 
the  final  stroke  of  discovery  is  only  prepared,  not  effected  by 
them.  The  brain  tracts  must,  of  their  own  accord,  shoot  the 
right  way  at  last,  or  we  shall  still  grope  in  darkness." 

Among  the  talents  of  the  discoverer,  perhaps  the  chief  is  to 
detect  similarity  in  phenomena  which,  to  casual  observation,  are 

unlike.     Of  this  the  capital  example  is  Frank- 
The  Detection      iin's   proof  that   lightning  and   common   fric- 
0fBLlnkean"S        tional  electricity  are  one  and  the  same.     Pro- 
Diversity,          fessor  Alexander  Bain,   in   "The   Senses  and 

the  Intellect,"  thus  describes  this  talent:— 
"When  it  first  occurred  to  a  reflecting  mind  that  moving  water 
had  a  property  identical  with  human  or  brute  force,  namely,  the 
property  of  setting  other  masses  in  motion,  overcoming  re- 
sistance and  inertia — when  the  sight  of  the  stream  suggested 
through  this  point  of  likeness  the  power  of  the  animal — a  new 
addition  was  made  to  the  class  of  prime  movers,  and  when  cir- 
cumstances permitted,  this  power  could  be  made  a  substitute  for 
the  others.  It  may  seem  to  the  modern  understanding,  familiar 
with  water-wheels  and  drifting  rafts,  that  the  similarity  here 
was  an  extremely  obvious  one.  But  if  we  put  ourselves  back 
into  an  early  state  of  mind,  when  running  water  affected  the 
mind  by  its  brilliancy,  its  roar,  and  irregular  devastation,  we  may 
easily  suppose  that  to  identify  this  with  animal  muscular  energy 
was  by  no  means  an  obvious  effect.  Doubtless  when  a  mind  arose, 
insensible  by  natural  constitution  to  the  superficial  aspects  of 
things,  and  having  withal  a  great  stretch  of  identifying  intellect, 
such  a  comparison  would  then  be  possible.  We  may  pursue  the 
same  example  one  stage  further,  and  come  to  the  discovery  of 
steam-power,  or  the  identification  of  expanding  vapor  with  the 


IMAGINATION  361 

previously  known  sources  of  mechanical  force.  To  the  common 
eye,  for  ages,  vapor  presented  itself  as  clouds  in  the  sky;  or,  as 
a  hissing  noise  at  the  spout  of  a  kettle,  with  the  formation  of  a 
foggy,  curling  cloud  at  a  few  inches'  distance.  The  forcing  up 
of  the  lid  of  a  kettle  may  also  have  been  occasionally  observed. 
But  how  long  was  it  ere  any  one  was  struck  with  parallelism 
of  this  appearance  with  a  blast  of  wind,  a  rush  of  water,  or  an 
exertion  of  animal  muscle?  The  discordance  was  too  great  to 
be  broken  through  by  such  a  faint  and  limited  amount  of  like- 
ness. In  one  mind,  however,  the  identification  did  take  place, 
and  was  followed  out  into  its  consequences.  The  likeness  had 
occurred  to  other  minds  previously,  but  not  with  the  same  re- 
sults. Such  minds  must  have  been  in  some  way  or  other  distin- 
guished above  the  millions  of  mankind,  and  we  are  endeavoring 
to  give  an  explanation  of  their  superiority.  The  intellectual 
character  of  Watt  contained  all  the  elements  preparatory  to  a 
great  stroke  of  similarity  in  such  a  case— a  high  susceptibility, 
both  by  nature  and  education,  to  the  mechanical  properties  of 
bodies;  ample  previous  knowledge,  or  familiarity;  and  indiffer- 
ence to  the  superficial  and  sensational  effects  of  things.  It  is 
not  only  possible,  however,  but  exceedingly  probable,  that  many 
men  possessed  all  these  accomplishments ;  they  are  of  a  kind  not 
transcending  common  abilities.  They  would  in  some  degree  at- 
tach to  a  mechanical  education,  as  a  matter  of  course.  That  the 
discovery  was  not  sooner  made  supposes  that  something  farther, 
and  not  of  common  occurrence  was  necessary ;  and  this  additional 
endowment  appears  to  be  the  identifying  power  of  similarity  in 
general ;  the  tendency  to  detect  likeness  in  the  midst  of  disparity 
and  disguise.  This  supposition  accounts  for  the  fact,  and  is  con- 
sistent with  the  known  intellectual  character  of  the  inventor  of 
the  steam  engine." 

A  discoverer  needs  for  success  much  more  than  identifying 
power.     Professor  John  Tyndall,  one  of  the  chief  expositors  of 
science  in  the  nineteenth  century,  speaks  thus 
of  the  part  played  by  an  investigator's  imagina-     The  Part  Played 
tion  : —  by  Imagination. 

"How  are  the  hidden  things  of  nature  to  be 
revealed  ?    How,  for  example,  are  we  to  lay  hold  of  the  physical 


362  THEORIES 

basis  of  light,  since,  like  that  of  life  itself,  it  lies  entirely  outside 
the  domain  of  the  senses?  Now  philosophers  may  be  right  in 
affirming  that  we  cannot  transcend  experience.  But  we  can,  at  all 
events,  carry  it  a  long  way  from  its  origin.  We  can  also  magnify, 
diminish,  qualify,  and  combine  experiences,  so  as  to  render  them 
fit  for  purposes  entirely  new.  We  are  gifted  with  the  power  of 
Imagination,  and  by  this  power  we  can  lighten  the  darkness 
which  surrounds  the  world  of  the  senses.  There  are  tories  even  in 
science  who  regard  imagination  as  a  faculty  to  be  feared  and 
avoided  rather  than  employed.  They  had  observed  its  action  in 
weak  vessels  and  were  unduly  impressed  by  its  disasters.  But 
they  might  with  equal  justice  point  to  exploded  boilers  as  an 
argument  against  the  use  of  steam.  Bounded  and  conditioned  by 
co-operative  reason,  imagination  becomes  the  mightiest  instrument 
of  the  physical  discoverer.  Newton's  passage  from  a  falling  apple 
to  a  falling  moon  was,  at  the  outset,  a  leap  of  the  imagination. 
When  William  Thomson  tries  to  place  the  ultimate  particles  of 
matter  between  his  compass  points,  and  to  apply  to  them  a  scale  of 
millimeters,  he  is  powerfully  aided  by  this  faculty.  And  in  much 
that  has  recently  been  said  about  protoplasm  and  life,  we  have 
the  outgoings  of  the  imagination  guided  and  controlled  by  the 
known  analogies  of  science.  In  fact,  without  this  power,  our 
knowledge  of  nature  would  be  a  mere  tabulation  of  co-existences 
and  sequences.  We  should  still  believe  in  the  succession  of  day 
and  night,  of  summer  and  winter ;  but  the  soul  of  Force  would  be 
dislodged  from  our  universe;  causal  relations  would  disappear, 
and  with  them  that  science  which  is  now  binding  the  parts  of  na- 
ture into  an  organic  whole." 

Professor  Tyndall  also  tells  us  how  sound  theories  are  divided 
from  unsound  :— 

"From  a .  starting-point  furnished  from  his  own  researches  or 

those  of  others,  the  investigator  proceeds  by  combining  intuition 

and  verification.    He  ponders  the  knowledge  he 

Theories  Must  possesses  and  tries  to  push  it  further,  he  guesses 
be  Verified,  and  checks  his  guess,  he  conjectures  and  con- 
firms or  explodes  his  conjecture.  These 
guesses  and  conjectures  are  by  no  means  leaps  in  the  dark;  for 
knowledge  once  gained  casts  a  faint  light  beyond  its  own  im- 


VERIFICATION  363 

mediate  boundaries.  There  is  no  discovery  so  limited  as  not  to 
illuminate  something  beyond  itself.  The  force  of  intellectual 
penetration  into  this  penumbral  region  which  surrounds  actual 
knowledge  is  not,  as  some  seem  to  think,  dependent  upon  method, 
but  upon  the  genius  of  the  investigator.  There  is,  however,  no 
genius  so  gifted  as  not  to  need  control  and  verification.  The  pro- 
foundest  minds  know  best  that  Nature's  ways  are  not  at  all  times 
their  ways,  and  that  the  brightest  flashes  in  the  world  of  thought 
are  incomplete  until  they  have  been  proved  to  have  their  counter- 
parts in  the  world  of  fact.  Thus  the  vocation  of  the  true  experi- 
mentalist may  be  defined  as  the  continued  exercise  of  spiritual  in- 
sight, and  its  incessant  correction  and  realization.  His  experi- 
ments constitute  a  body,  of  which  his  purified  intuitions  are,  as  it 
were,  the  soul." 

Theories,  however  helpful,  should  be  held  with  a  loose  hand. 
He  declares : — 

"In  our  conceptions  and  reasonings  regarding  the  forces  of 
nature,  we  perpetually  make  use  of  symbols  which,  whenever 
they  possess  a  high  representative  value  we  dignify  with  the  name 
of  theories.  Thus,  prompted  by  certain  analogies,  we  ascribe  elec- 
trical phenomena  to  the  action  of  a  peculiar  fluid,  sometimes  flow- 
ing, sometimes  at  rest.  Such  conceptions  have  their  advantages 
and  their  disadvantages;  they  afford  peaceful  lodging  to  the  in- 
tellect for  a  time,  but  they  also  circumscribe  it,  and  by-and-by, 
when  the  mind  has  gro.wn  too  large  for  its  lodging,  it  often  finds 
difficulty  in  breaking  down  the  walls  of  what  has  become  its 
prison  instead  of  its  home." 

In  the  same  vein  was  the  remark  of  Michael  Faraday :— "I  can- 
not but  doubt  that  he  who  as  a  mere  philosopher  has  most  power 
of  penetrating  the  secrets  of  nature,  and  guessing  by  hypothesis 
at  her  mode  of  working,  will  also  be  most  careful  for  his  own  safe 
progress  and  that  of  others,  to  distinguish  the  knowledge  which 
consists  of  assumption,  by  which  I  mean  theory  and  hypothesis, 
from  that  which  is  the  knowledge  of  facts  and  laws." 

He  once  wrote  a  letter  on  ray-vibrations  to  Mr.  Richard  Phil- 
lips ;  at  its  close  he  said  :— "I  think  it  likely  that  I  have  made  many 
mistakes  in  the  preceding  pages,  for  even  to  myself  my  ideas  on 
this  point  appear  only  as  the  shadow  of  a  speculation,  or  as  one  of 


364  THEORIES 

those  impressions  on  the  mind  which  are  allowable  for  a  time  as 
guides  to  thought  and  research.  He  who  labors  in  experimental 
inquiries,  knows  how  numerous  these  are,  and  how  often  their- 
apparent  fitness  and  beauty  vanish  before  the  progress  and  de- 
velopment of  real  natural  truth." 

"Summing  up,  then,"  says  Professor  William  Stanley  Jevons, 
in  "Principles  of  Science,"  "it  would  seem  as  if  the  mind  of  the 
great  discoverer  must  combine  almost  contradictory  attributes.  He 
must  be  fertile  in  theories  and  hypotheses,  and  yet  full  of  facts 
and  precise  results  of  experience.  He  must  entertain  the  feeblest 
analogies,  and  the  merest  guesses  at  truth,  and  yet  he  must  hold 
them  worthless  until  they  are  verified  in  experiment.  When  there 
are  any  grounds  of  probability  he  must  hold  tenaciously  to  an  old 
opinion,  and  yet  he  must  be  prepared  at  any  moment  to  relinquish 
it  when  a  single  clear  contradictory  fact  is  encountered.  'The 
philosopher,'  says  Faraday,  'should  be  a  man  willing  to  listen  to 
every  suggestion,  but  determined  to  judge  for  himself.  He  should 
not  be  biassed  by  appearances ;  have  no  favorite  hypotheses ;  be 
of  no  school ;  and  in  doctrine  have  no  master.  He  should  not  be 
a  respecter  of  persons,  but  of  things.  Truth  should  be  his  primary 
object.  If  to  these  qualities  be  added  industry,  he  may  indeed 
hope  to  walk  within  the  veil  of  the  temple  of  nature.' ' 

Character,  no  less  than  mind  of  the  highest  order,  ever  distin- 
guishes the  great  researcher.  Says  Professor  Tyndall :— "Those 
who  are  unacquainted  with  the  details  of  scientific  investigation, 
have  no  idea  of  the  amount  of  labor  expended  on  the  determina- 
tion of  those  numbers  on  which  important  calculations  or  in- 
ferences depend.  They  have  no  idea  of  the  patience  shown  by  a 
Berzelius  in  determining  atomic  weights;  by  a  Regnault  in  de- 
termining co-efficients  of  expansion ;  or  of  a  Joule  in  determining 
the  mechanical  equivalent  of  heat.  There  is  a  morality  brought  to 
bear  upon  such  matters,  which,  in  point  of  severity,  is  probably 
without  a  parallel  in  any  other  domain  of  intellectual  action." 

Surely  there  was  a  union  of  the  highest  character  and  of  con- 
summate ability  in  Stas,  the  Belgian  chemist,  who  eliminated  from 
his  chemicals  every  trace  of  that  pervasive  element,  sodium,  so 
thoroughly,  that  even  its  spectroscopic  detection  was  impossible. 


BROAD  HORIZONS  365 

The  greatest  man  of  science  that  England  has  given  to  the 
world  was  Sir  Isaac  Newton,  second  only  to  him  was  Dr.  Thomas 
Young,  who  established  the  wave-theory  of 
light,  who  deciphered  Egyptian  hieroglyphics  A  word  for 
with  marvelous  skill,  and  was  withal  an  accom-  Discursiveness. 
plished  physician.  In  1801  he  was  appointed 
to  the  professorship  of  natural  philosophy  in  the  Royal  Institu- 
tion, London,  founded  in  1800  by  Benjamin  Thompson,  Count 
Rumford,  a  native  of  Woburn,  Massachusetts.  When  Dr.  Young 
died,  Davies  Gilbert,  president  of  the  Royal  Society,  delivered  a 
commemorative  address  in  the  course  of  which  he  declared  that 
in  Young's  opinion  it  is  probably  most  advantageous  to  mankind 
that  the  researches  of  some  inquirers  should  be  concentrated  with- 
in a  given  compass,  but  that  others  should  pass  more  rapidly 
through  a  wider  range.  He  believed  that  the  faculties  of  the  mind 
were  more  exercised,  and  probably  rendered  stronger,  by  going 
beyond  the  rudiments,  and  overcoming  the  great  elementary  diffi- 
culties, of  a  variety  of  studies,  than  by  employing  the  same  number 
of  hours  in  any  one  pursuit— that  the  doctrine  of  the  division  of 
labor,  however  applicable  to  material  product,  was  not  so  to  in- 
tellect, and  that  it  went  to  reduce  the  dignity  of  man  in  the  scale 
of  rational  existences.  He  thought  it  impossible  to  foresee  the 
capabilities  of  improvement  in  any  science,  so  much  of  accident 
having  led  to  the  most  important  discoveries,  that  no  man  could 
say  what  might  be  the  comparative  advantage  of  any  one  study 
rather  than  of  another;  though  he  would  have  scarcely  recom- 
mended the  plan  of  his  own  course  as  a  model  to  others,  he  still 
was  satisfied  in  the  method  which  he  had  pursued. 


CHAPTER  XXV 
THEORIZING-Continued 

Analogies  have  value  .  .  .  Many  principles  may  be  reversed  with  profit 
.  .  .  The  contrary  of  an  old  method  may  be  gainful  .  .  .  Judgment  gives 
place  to  measurement,  and  then  passes  to  new  fields. 

A  CONVICTION  that  has  over  and  over  again  served  the  dis- 
coverer assures  him  that  like  causes  underlie  effects  which 
seem  diverse.    When  Thomas  Young  observed  the  recurrent  bands 
of  darkness  due  to  interferences  of  light,  he  at  once  detected  a 
parallel  to  the  beats  by  which  interferences  of 

Analogy  as  a         SOund  produce  silence.     He  was  therefore  per- 
Guide. 

suaded  that  light  moves  in  waves  as  does  sound, 

that  it  is  not,  as  Newton  supposed,  a  material  emission.    A  chapter 
might  be  filled  with  examples  of  the  same  kind :  let  one  suffice. 

If  an  ordinary  clothes-line,  say  twenty  feet  long,  receives  a 
wave-impulse  from  the  hand  at  one  end,  the  motion  will  proceed 
to  the  other  end  as  a  series  of  waves.  If  a  rope  twice  as  heavy 
is  used,  a  larger  part  of  the  original  impulse  will  be  received  at 
the  remote  end  than  in  the  first  experiment.  Of  course,  there 
comes  a  limit  to  the  thickness  of  the  rope  which  may  be  thus  em- 
ployed ;  we  must  not  choose  a  ship's  cable  for  instance,  but  the 
rope  most  effective  in  results  is  much  heavier  than  one  would  sup- 
pose before  trial.  Lord  Rayleigh,  in  his  treatise  on  the  theory 
of  sound,  has  shown  that  according  to  Lagrange  it  is  unnecessary 
to  thicken  a  cord  when  we  wish  to  add  to  its  weight ;  as  an  alter- 
native we  may  fasten  weights  upon  it  at  due  intervals,  the  whole 
having  less  mass  than  if  we  used  a  heavy  rope  of  equal  effective- 
ness. Just  what  intervals  are  best  will  depend  upon  the  thickness 
and  rigidity  of  the  cord,  upon  its  length,  the  amount  and  kind  of 
wave  committed  to  it,  as  shown  by  Professor  Michael  I.  Pupin  of 
Columbia  University,  New  York,  who  extended  the  mathematical 
problem  dealth  with  by  Lagrange  and  Lord  Rayleigh.  In  the  sin- 

366 


PUPIN  TELEPHONY 


367 


gular  efficiency  of  transmission  thus  studied  he  saw  a  principle 
which,  by  analogy,  he  believed  to  hold  true  in  the  electrical  field 
as  in  mechanics.  This  principle  he  has  illustrated  in  his  paper 
published  in  the  Proceedings  of  the  American  Institute  of  Elec- 
trical Engineers,  1900,  page  215.  In  A  of  the  accompanying  fig- 
ure, derived  from  that  paper,  is  a  tuning  fork,  C,  with  its  handle 


Prof.  Pupin's  diagram  explaining  his  system  of  long 
distance  telephony. 


rigidly  fixed.  To  one  of  its  prongs  is  attached  a  flexible  inex- 
tensible  cord,  bd.  Let  the  fork  vibrate  steadily  by  any  suitable 
means.  The  motion  of  the  cord  will  be  a  wave  motion,  as  in  B. 
The  attenuation  of  the  wave  as  it  dies  down  is  represented  in  C. 
Experiments  show  that,  other  things  being  equal,  increased  density 
of  the  string  will  diminish  attenuation,  because  a  larger  mass  re- 
quires a  smaller  velocity  in  order  to  store  up  a  given  quantity  of 
kinetic  energy,  and  smaller  velocity  brings  with  it  a  smaller  fric- 
tional  loss.  Moreover,  as  the  string  is  increased  in  density,  its 
wave-length  is  shortened. 

Suppose  now  that  we  attach  a  weight,  say  a  ball  of  beeswax,  at 
the  middle  point  of  the  string,  so  as  to  increase  the  vibrating  mass. 
This  weight  will  become  a  source  of  reflections  and  less  wave 


368  THEORIES 

energy  will  reach  the  farther  end  of  the  string  than  before.  Sub- 
divide the  beeswax  into  three  equal  parts  and  place  them  at  three 
equi-distant  points  along  the  cord.  The  efficiency  of  transmission 
will  be  better  now  than  when  all  the  wax  was  concentrated  at  a 
single  point.  By  subdividing  still  further  the  efficiency  will  be 
yet  more  improved ;  but  a  point  is  soon  reached  when  further  sub- 
divisions produce  very  slight  improvement.  This  point  is  reached 
when  the  loaded  cord  vibrates  nearly  like  a  uniform  cord  of  the 
same  mass,  tension,  and  f rictional  resistance ;  such  a  cord,  bearing 
12  small  weights  of  beeswax,  is  represented  as  D  when  at  rest,  as 
E  when  in  motion.  .  .  .  It  is  impossible  so  to  load  a  cord 
as  to  make  it  suitable  for  waves  of  all  lengths;  but  if  the  dis- 
tribution of  the  loads  satisfies  the  requirements  of  a  given  wave- 
length, it  will  also  satisfy  them  for  all  longer  wave-lengths. 

A  cord  of  this  kind  has  mechanical  analogy  with  an  electrical 
wave  conductor.  In  a  wire  transmitting  electricity  inductance 
coils  may  be  so  placed  as  to  have  just  the  effect  of  the  bits  of  wax 
attached  to  the  cord  in  our  illustration ;  in  both  cases  the  waves 
are  transmitted  more  fully  and  with  less  blurring  than  in  an  un- 
loaded line.  The  mathematical  law  of  both  cases  is  the  same. 
It  was  in  ascertaining  that  law  so  as  to  know  where  to  place  his 
inductance  coils  that  Professor  Pupin  arrived  at  success.  Pre- 
ceding inventors,  missing  this  law,  came  only  to  failure.  He  con- 
structed an  artificial  cable  of  250  sections,  each  consisting  of  a 
sheet  of  paraffined  paper  on  both  sides  of  which  was  a  strip  of 
tin-foil,  the  whole  fairly  representing  a  cable  250  miles  in  length. 
At  each  of  the  250  joints  in  the  course  of  this  artificial  circuit  he 
inserted  a  twin  inductance  coil  wound  on  one  spool  125  milli- 
metres broad  and  high,  and  separated  by  cardboard  1/64  inch 
thick.  Each  coil  had  580  turns  of  No.  20  Brown  &  Sharpe  wire. 
Just  as  with  the  weighted  rope  this  circuit  transmitted  its  current 
much  more  efficiently  than  if  the  inductance  coils  had  been  absent. 

This  artificial  cable,  when  without  coils,  through  a  distance 
equal  to  fifty  miles  of  ordinary  line  worked  well,  up  to  seventy- 
five  miles  it  served  fairly  well,  but  proved  impracticable  at  100 
miles,  and  impossible  at  distances  exceeding  112  miles:  all  this 
in  exact  correspondence  with  an  actual  line  of  the  same  length. 
Over  a  uniform  telephone  line  an  increase  of  distance  interferes 


REVERSIBILITY  369 

with  the  transmission  of  speech,  not  only  by  diminishing  the 
volume  of  sound,  but  also  from  the  rapid  loss  of  articulation.  At 
first  this  manifests  itself  as  an  apparent  lowering  of  vocal  pitch. 
In  Professor  Pupin's  experiments  an  assistant's  voice  at  the  end 
of  75  miles  of  uniform  cable  sounded  like  a  strong  baritone;  at 
100  miles  it  became  drummy  so  that  it  was  understood  with  diffi- 
culty, although  the  speaker  had  his  mouth  close  to  the  trans- 
mitter, and  spoke  as  loudly  as  if  he  were  addressing  a  large 
audience.  At  more  than  112  miles  nothing  but  the  lowest  notes 
of  his  voice  could  be  heard,  the  articulation  was  entirely  gone. 
As  soon  as  the  coils  were  inserted  the  drumminess  ceased,  and 
conversation  could  be  carried  on  as  rapidly  as  one  chose  through 
the  whole  circuit  of  1 12  miles.  Drumminess  is  due  to  the  oblitera- 
tion of  the  overtones,  long  distance  transmission  weakening  these 
overtones  much  more  than  it  does  the  low  fundamental  tones. 
The  addition  of  coils  makes  the  rate  of  weakening  the  same  for 
all  vibrations,  hence  the  transmitted  sound  has  the  same  character 
at  the  end  of  the  line  as  at  the  beginning. 

In  practice  Professor  Pupin's  method  has  proved  a  remarkable 
success.  In  ordinary  circuits  it  reduces  materially  the  quantity 
of  wire  necessary.  Where  a  circuit  is  unusually  long  it  assures 
clearness  of  tones  or  of  signals  at  distances  previously  out  of 
the  question.  It  makes  possible  telephony  across  the  Atlantic :  a 
cable  for  this  service  would  cost  only  one  fourth  more  than  an 
ordinary  telegraphic  cable  as  now  laid  and  used.  A  decided  ad- 
vantage is  reaped  by  its  use  in  underground  cables,  liable  as  they 
are  to  a  serious  blurring  of  currents  at  distances  comparatively 
short.  The  intervals  at  which  inductance  coils  should  be  placed 
depend  upon  the  circumstances  of  each  case.  These  are  dis- 
cussed by  Professor  Pupin  in  the  paper  here  mentioned. 

Analogy  in  many  a  path  such  as  that  of  Professor  Pupin  has 
served  as  a  guide  to  the  discoverer  and  inventor.     Equally  gain- 
ful has  been  the  conviction  that  many  rules 
work  both  ways,  so  that  ingenuity  has  only  to     RUies  that  Work 
execute  the  converse  or  the  reverse  of  a  fa-        Both  Ways, 
miliar  task  in  order  to  abridge  toil,  or  reach  a 
prize  wholly  new. 

A  crow  wishes  to  get  at  a  clam  which  it  has  dug  out  of  the  sand. 


376  THEORIES 

To  break  the  stout  shell  is  beyond  the  strength  of  its  bill,  so  the 
knowing  bird  flies  aloft,  lets  the  clam  fall  on  a  rocky  beach  or  a 
stone  and  forthwith  enjoys  a  meal.  It  makes  no  difference 
whether  a  hammer  falls  on  the  shell,  or  the  shell  falls  on  a  ham- 
mer :  the  crow  takes  the  one  method  within  its  power.  So  with 
the  wood-chopper  whose  axe  becomes  imbedded  in  a  stick  of 
birch  or  maple :  he  lifts  wood  and  axe  together  as  high  as  he  can, 
then  lets  the  axe  fall  on  its  back,  when  the  shock  instantly  tears 
the  stick  apart.  Drilling  in  a  lathe  is  usually  executed  by  the 
screw  of  the  poppet  advancing  during  the  process.  In  boring 
long  holes,  the  object  to  be  bored  is  rotated  and  moved  in  a 
straight  liner  while  the  tool  advances  without  revolving.  In  an 
emergency  William  Fairbairn,  the  famous  engineer,  had  in  hand 
a  large  task  of  riveting.  He  took  a  punching  machine,  reversed 
its  action,  and  had  a  riveting  machine  which  turned  out  work 
twelve  times  as  fast  as  a  skilful  workman. 

As  in  the  machine  shop  so  in  transportation.  One  of  the  notions 
of  the  pioneer  railway  engineers  in  England  was  that  their  rails 
must  be  flanged,  for  how  else  could  wheels  remain  on  the  track  ? 
But  somebody  with  breadth  of  view-point  asked,  Why  not  leave 
the  rail  flat,  or  nearly  so,  and  put  the  flange  on  the  wheel,  an 
easier  thing  to  do?  Accordingly  to  the  wheel  the  flange  went 
and  there  it  stays,  to  remind  the  traveler  of  the  Eastern  maxim: 

'To  him  who  is  well  shod 
it  is  as  if  the  whole  world 
were  covered  with  leather." 
In  many  tasks  we  have  a 
like  choice  of  methods.  We 
wish  to  measure  the  velocity 
of  a  stream ;  if  we  immerse 
a  bent  glass  tube  so  that  its 
Water  heightened        Water  lowered         horizontal      part      is      up- 
in  tube.  in  tube.  stream,  the  height  to  which 

the  water  rises  in  the  up- 
right half  of  the  tube  will  tell  us  what  we  wish  to  know ;  if  we 
reverse  the  tube,  a  sinking  instead  of  a  rising  in  the  upright  glass 
will  measure  the  speed  of  our  current. 

For  many  years  turbines  have  proved  themselves  better  than 


BURDENS  LIGHTENED  371 

Other  water-wheels,  so  that  wherever  an  old-fashioned  breast- 
wheel  still  goes  its  creaking  round,  there  the 

sketcher  seizes  the  picturesque  outlines  of  a 

.    .  t  A  Reversed. 

motor  whose  remaining  days  are  few.  A  tur- 
bine in  carefully  curved  vanes  gets  from  falling  water  all  the 
power  it  holds;  when  the  task  is  to  lift  water,  then  this  very 
turbine,  reversed  in  direction,  is  the  Worthington  pump,  the  most 
efficient  water-lifter  known.  The  rules  for  construction  are  the 
same  whether  we  start  with  falling  water  and  derive  power  from 
it,  or  begin  with  power  and  raise  water  thereby..  Quite  as  pic- 
torial as  a  breast-wheel  is  a  wind-mill,  the  older  the  better,  thinks 
the  artist  as  he  views  its  weather-beaten  frame.  Much  later  than 
the  wind-mill  as  a  device  is  its  counterpart,  the  fan-blower;  the 
lines  most  effective  for  the  one  are  also  best  for  the  other.  Much 
more  effective  than  the  old-time  mills  of  but  four  arms  are  new 
mills  whose  whole  circle  is  covered  by  blades.  Fan-blowers  with 
a  like  multiplicity  of  vanes,  yield  most  duty. 

For  ages  one  of  the  observations  of  every  day  has  been  that 
a  column  of  water  exerts  pressure  in  proportion  to  its  height. 
Usually  this  pressure  is  thought  of  as  being 
exerted  downward,  but  if  a  pipe,  filled  with          Hydraulic 

Pressure  as  a 
water  at  great  pressure,  be  curved  upward  at      counterbalance. 

its  base,  then  the  contained  liquid  presses  up- 
ward. Mark  the  gain  of  thus  varying  a  little  from  the  ordinary 
view  point  of  a  case.  In  1883  Mr.  J.  F.  Holloway,  of  California, 
set  up  a  turbine  with  its  stream  admitted  from  below  and  moving 
upward  through  the  vanes  of  the  machine.  He  thus  obliged  the 
water  pressure  to  aid  in  supporting  the  wheel,  materially  diminish- 
ing its  friction  through  thus  counterbalancing  its  weight.  This 
plan  has  been  adopted  at  Niagara  Falls  for  the  gigantic  turbines 
there  erected,  among  the  most  powerful  in  the  world. 

That  simple  appliance,  a  garden  squirt,  exemplifies  two  im- 
portant kinds  of  apparatus,  one  the  converse  of  the  other.     Fill 
the  cylinder  with  water,  force  the  piston  along 
its  course,  and  you  have  a  pump.    Admit  water    Engine  and  Pump, 
under  pressure,  as  from  a  city  faucet,  and  it 
drives  the  piston  of  a  motor ;  in  principle  such  is  the  mechanism 
of  thousands  of  motors  in  London,  using  water  under  a  pressure 


372  THEORIES 

of  500  pounds,  or  so,  to  the  square  inch.  An  apparatus,  essentially 
the  same,  when  supplied  with  steam  or  gas  becomes  the  familiar 
engine  at  work  in  uncounted  factories  and  mills.  It  was  a  great 
advance  in  steam  engine  design  when  the  single  cylinder  of  Watt 
was  replaced  by  two  or  more  cylinders,  using  steam  at  high  in- 
stead of  low  pressure.  Thus  apportioned  in  a  series  of  cylinders 
the  steam  is  not  nearly  as  much  cooled,  with  loss  of  working 
power,  as  when  but  one  cylinder  is  used.  So  likewise,  it  is  best  to 
divide  the  compressing  of  air  into  two  or  more  stages,  so  that  at 
each  stage  the  air  may  be  cooled,  and  thus  more  easily  compressed 
than  if  a  single  operation  completed  the  business.  The  best  air 
compressor  is  virtually  the  converse  of  a  steam  engine. 

Of  late  years  reciprocating  machinery,  of  one  kind  and  an- 
other, has  had  to  give  place  to  rotary  designs.  In  these,  as  in 
their  predecessors,  are  striking  cases  of  rules  that  work  both 
ways.  If  steam  at  high  pressure  is  fully  to  yield  its  energy  in  a 
Parsons- Westinghouse  turbine,  for  example,  the  vanes  must  be 
rightly  curved,  and  there  must  be  a  succession  of  them  in  circles 
gradually  widened  so  that  the  steam  may  part  with  its  energy,  a 
step  at  a  time.  In  mining,  in  metallurgy,  in  many  another  great 
industry,  compressed  air  is  required  in  huge  volumes.  For  its 
production  Mr.  Parsons  has  invented  an  apparatus  virtually  the 
twin  of  his  steam  turbine,  only  that  it  runs  in  a  reversed  direction ; 
it  may  be  directly  yoked  to  a  steam  turbine. 

Currents  of  air  much  less  forceful  than  those  of  steam  in  a 
turbine  are  generated  by  the  electric  fans  of  our  shops  and  offices. 

When  their  vanes  move  as  the  hands  of  a  clock, 
Fans.  a    breeze    comes    toward    you;    reverse    their 

motion  and  the  stream  blows  away  from  you. 
Place  such  a  fan  in  the  side  of  a  box  otherwise  closed;  driven 
in  one  direction  the  vanes  force  air  into  the  box;  driven  the  op- 
posite way  the  vanes  remove  air  from  the  box.  Powerful  currents 
of  this  kind,  such  as  stream  from  a  Sturtevant  blower,  are  used 
for  blast  furnaces  and  the  largest  steam  installations.  The  en- 
gineer chooses  between  two  methods ;  he  can  seal  up  the  fire-room 
and  force  in  air  which  will  find  its  way  through  the  grate-bars  to 
the  fuel,  or  he  places  a  fan  in  the  smoke-stack  to  induce  a  current 


ELECTRICAL  REVERSIBILITY       373 

by  exhaustion.  In  New  York  and  London  underground  pneu- 
matic tubes  carry  letters  to  and  from  the  post-offices.  When  the 
central  engine  works  its  fans  exhaustively,  water  may  be  drawn 
into  the  tubes  from  the  streets  so  as  to  do  much  harm.  When  the 
ground  is  thoroughly  dry  it  is  best  to  exhaust  the  air  at  one  end 
of  the  line  and  compress  it  at  the  other.  This  union  of  a  push 
and  a  pull  resembles  Lord  Kelvin's  plan  in  ocean  telegraphy,  by 
which  a  cable  is  first  connected  with  the  negative  pole  of  a  battery 
and  then,  for  a  signal,  made  to  touch  the  positive  pole.  With  its 
path  thus  cleared,  a  message  pulses  along  at  a  redoubled  pace. 

Electrical  art  teems  with  rules  that  work  both  ways.  Oersted 
observed  that  a  current  traversing  a  wire  deflects  a  nearby  com- 
pass needle.  Faraday,  with  the  guiding  law  of 
reciprocity  ever  in  mind,  forcibly  deflected  a  Reci^roctt 
magnetic  needle  so  as  to  create  a  current  in  a 
neighboring  wire  by  the  motion  of  his  hand.  He  thus  dis- 
covered magneto-electricity,  in  Tyndall's  opinion  the  greatest  re- 
sult ever  obtained  by  an  experiment.  On  the  simple  principle  then 
discovered  by  Faraday  are  built  the  huge  generators  that  revolve 
at  Niagara,  at  power-houses  large  and  small  throughout  the 
world,  for  the  production  of  electricity  by  mechanical  motion.  A 
compass  needle  has  a  field,  or  breadth  of  influence,  surrounding  its 
surface,  which  is  small  and  weak.  A  monster  magnet  in  a  gen- 
erator has  a  field  at  once  large  and  strong.  When  an  electrical 
conductor,  such  as  a  coil  of  copper  wire,  is  forcibly  rotated  in 
that  field,  powerful  currents  of  electricity  arise  in  the  wire, 
equivalent  as  energy  to  the  mechanical  effort  of  rotation.  Take 
another  case :  a  current  decomposes  water ;  the  resulting  gases  as 
they  combine  yield  just  such  a  current  as  that  which  parted  them. 
Join  a  strip  of  bismuth  to  a  strip  of  antimony,  and  let  a  current 
traverse  the  pair;  the  junction  will  become  heated.  At  another 
time,  using  no  current,  touch  that  joint  with  the  hand  for  a 
moment;  the  communicated  warmth,  though  trifling  in  amount, 
creates  a  current  plainly  revealed  by  a  galvanometer,  affording 
a  delicate  means  of  detecting  minute  changes  of  temperature.  In 
1874  M.  Gramme  showed  four  of  his  dynamos  at  the  Vienna  Ex- 
hibition. M.  Fontaine,  an  electrician,  saw  a  pair  of  loose  wires 


374  THEORIES 

near  one  of  the  machines  and  attached  them  to  its  terminals ;  the 
other  ends  of  the  wires  happened  to  be  connected  with  a  dynamo 
in  swift  rotation.  Immediately  the  newly  attached  machine  be- 
gan to  revolve  in  a  reverse  direction  as  a  motor.  Thus  by  an  acci- 
dent, wisely  followed  up,  did  electricity  add  itself  to  motive 
powers,  establishing  an  industry  now  of  commanding  importance. 
In  the  chemical  effects  of  a  current  we  have  parallel  facts.  Ex- 
pose a  nickel-iron  plate  to  the  alkaline  bath  of  an  Edison  storage 
cell ;  at  once  the  metal  begins  to  dissolve,  yielding  a  current.  Now 
send  a  slightly  stronger  current  into  that  plate;  forthwith  the 
plate  picks  out  iron-nickel  from  its  compounds  in  the  liquid,  grow- 
ing fast  to  its  original  bulk.  So  many  cases  of  this  kind  occur 
that  chemists  believe  that  synthesis  and  electrolysis  are  always 
counterparts.  Be  that  as  it  may,  we  must  remember  that  often 
chemical  action  is  much  more  intricate  than  it  seems  to  be  at  first 
sight.  Thus  in  dry  air,  or  even  in  dry  oxygen,  iron  is  unat- 
tacked;  but  bring  in  a  little  moisture  and  at  once  oxidation  pro- 
ceeds with  rapid  pace.  So  with  the  combustible  gases  emerging 
from  the  throat  of  a  blast  furnace ;  they  refuse  to  burn  until  they 
meet  a  whiff  of  steam,  when  they  instantly  burst  into  flame. 
Chemical  energy  usually  moves  in  a  labyrinth  which  the  chemist 
may  be  able  to  thread  only  in  one  direction.  A  retracing  of  his 
steps  is  for  the  day  when  he  will  know  much  more  than  he  does 
now. 

Properties  purely  physical,  and  therefore  much  simpler  than 
those  studied  by  the  chemist,  offer  us  noteworthy  instances  of 

rules  that  work  both  ways.  For  years  the  walls 
Ovens  and  Safes,  and  doors  of  safes  and  bank  vaults  have  been 

filled  with  gypsum  as  a  substance  all  but  im- 
pervious to  heat.  To-day  Norwegian  cooking  chests,  on  much 
the  same  principle,  are  attracting  public  attention  by  their  econ- 
omy. A  pot  is  filled  with,  let  us  say,  the  materials  for  soup,  it  is 
brought  to  a  boil,  and  then  placed  in  a  chest  thickly  clad  with  a 
non-conducting  coat  of  felt  or  even  of  hay,  as  illustrated  on  page 
189.  In  an  hour  or  so  a  capital  soup  is  found  to  have  cooked  it- 
self simply  by  its  own  retained  heat.  A  resource  long  familiar 
to  the  builder  of  safes  and  strong-boxes  is  thus  taken  into  house- 
hold service  with  much  profit.  It  is  plain  that  whatever  obstructs 


Copyright.  Pach  Bros..  New  York. 

THOMAS   ALVA   EDISON,    1906. 
ORANGE,  NEW  JERSEY. 


OBSTACLES  TO  HEAT  375 

the  passing  of  heat  may  be  employed  either  to  keep  it  in  or  keep  it 
out.  For  years  inventors  busied  themselves  in  finding  non-con- 
ductors wherewith  to  cover  steam-pipes  and  steam-boilers.  To- 
day, in  cold  storage  plants,  these  non-conductors  are  just  as  use- 
ful in  covering  pipes  filled  with  circulating  liquids  of  freezing 
temperatures.  Take  a  parallel  case  in  the  field  of  physical  re- 
search. In  1873  Dulong  and  Petit  in  their  measurement  of  heat 
avoided  losses  of  heat  with  a  new  approach  to  perfection  by  using 
glass  vessels  one  inside  another,  with  exhausted  spaces  in  be- 
tween. In  1892  Professor  Dewar  applied  this  device  to  keeping 
liquefied  gases,  of  extremely  low  temperatures,  from  being 
warmed  by  surrounding  bodies,  an  aim  just  the  converse  of  that 
of  Dulong  and  Petit.  Often,  as  in  these  cases,  the  applications  of 
a  quality  may  come  in  pairs ;  one  invention  may  suggest  its  twin. 

This  convertibility  of  principle  may  be  observed  as  clearly  in  the 
phenomena  of  nature  as  in  the  creations  of  ingenuity.  Water 
expands  as  it  freezes;  when  this  expansion  takes  place  freely, 
the  freezing  temperature  is  o°  C.,  but  when  expansion  is  resisted, 
as  when  the  water  is  confined  in  a  strong  gun-barrel,  the  freezing 
temperature  is  lowered,  for  now  the  ice  has  to  do  work  in  the  act 
of  crystallization.  So  with  the  boiling  points  of  liquids ;  they  rise 
as  atmospheric  pressure  increases,  they  fall  as  atmospheric 
pressure  is  reduced.  A  prospector  on  Pike's  Peak  cannot  boil 
an  egg  in  his  kettle.  Next  day  he  descends  a  mine  in  the  valley, 
to  find  the  boiling  point  higher  than  when  he  built  his  fire  beside 
the  mouth  of  the  mine. 

Take  another  example  of  inversion,  this  time  in  the  field  of 
mensuration.     Every   schoolboy  knows    that   cubes    respectively 
one,  two,  three,  and  four  inches  in  diameter 
have     contents     respectively    of     one,     eight,   Cub*  *°°****ily 
twenty-seven,    and    sixty- four    cubic    inches; 
that  is,  the  contents  vary  as  the  cubes  of  the  diameters  of  these 
solids.     This  is  true  of  all  solids  alike  in  form.     Cones,  therefore, 
which  have  an  angle  of  let  us  say  fifteen  degrees  at  the  apex, 
vary  in  contents  as  the  cube  of  their  heights.      Cones  usually  are 
looked  at  as  they  rest  on  their  bases;  it  is  worth  while  to  consider 
them  reversed,  pointing  downward.     An  inverted  cone,  duly  sup- 
ported on  a  frame  allowing  motion  upward  and  downward,  and 


376 


THEORIES 


dipping  into  a  cylinder  partly  filled  with  water,  is  a  simple  means 
of  extracting  cube  root  within  say  one  and  ten  as  limits.     The 


Cube-root  extractor. 

The  cone  displaces  water  as  the  cube  of  its  depth  of  immersion,  in  this 
case  within  I  and  3  as  limits. 


cone  should  be  marked  off  into  tenths,  and  the  cylinder,  between 
high  and  low-water,  into  thousandths.  On  a  similar  plan  a 
tapering  wedge  acts  as  a  square-root  extractor,  displacing  water 
as  the  square  of  its  depth  of  immersion. 


READING  THE  STORY  OF  A  TOOL  377 


From  Effect  to 
Cause. 


A  mechanic,  no  less  than  a  geometer,  may  show  sagacity  in 
taking  up  a  question  in  reverse,  and  reasoning  from  effect  to 
cause.  An  expert  printer  examines  a  spoiled 
sheet  as  it  leaves  the  press,  observing  that  it  is 
smeared  and  crumpled  with  a  decided  skew. 
At  once  he  stops  the  machinery  and  puts  his  finger  on  a  lever  that 
has  become  crooked,  or  on  the  wheel  that  has  been  strained  out 
of  true.  Mr.  Joseph  V. 
Woodworth  says  of  milling 
cutters: — "When  a  cutter  is 
broken  by  being  wrongly 
run  backwards  on  to  the 
work,  the  breakage  is  char- 
acteristic. Although  the  man 
who  broke  it  will  be  ab- 
solutely sure  that  it  ran  in 
the  right  direction,  the 
cracks  down  the  face  of  the 
teeth  tell  a  different  story." 

In  his  manual  on  steel, 
Mr.  William  Metcalf  reads 
a  record  equally  legible  to  a 
trained  eye:— "If  an  axe, 
after  tempering,  is  found 
cracked  near  the  corners  of 
its  edge,  these  corners  have 

been  hotter  than  the  middle  of  the  blade.  If  a  crack  appears  at 
the  middle  of  the  edge,  there  the  heat  was  greater  than  at  the 
corners;  snipping  and  comparing  the  grains  will  tell  the  story. 
If  a  somewhat  straight  crack  is  noticed,  near  the  edge  and  parallel 
thereto,  the  chances  are  that  the  crack  indicates  a  seam." 

At  this  point  let  us  for  a  few  moments  leave  the  field  of 
mechanics,  and  notice  how  inferring  cause  from  effect  may  aid 
students  of  rocks,  of  the  heavens,  of  the  human  frame.  A  geolo- 
gist, observing  a  dense  limestone,  learns  how  severe  the  pressure 
which  brought  loose  sediment  to  this  compactness.  In  the  glass- 
like  texture  of  quartz  he  finds  an  equally  plain  record  of  intense 
heat.  The  scorings  on  rock-surfaces,  in  lines  from  northward 


Square-root  extractor. 
Wedge  displaces  water  as  the  square 
of  its  depth  of  immersion. 


378  THEORIES 

to  southward,  disclose  to  him  the  paths  in  which  ages  ago  the 
glaciers  moved  from  their  birth-places  in  the  polar  zones.  In 
astronomy  a  feat  of  inference  incomparably  more  difficult  was 
accomplished  by  John  Couch  Adams  and  Urbain  Leverrier,  each 
independently  of  the  other.  The  orbit  of  Uranus  displayed  cer- 
tain minute  irregularities  which  they  referred  to  a  planet,  at  that 
time  not  as  yet  observed,  whose  place  they  indicated.  Their  re- 
markable inference  was  verified  by  the  discovery  of  Neptune  on 
September  23,  1846. 

In  a  path  remote  indeed  from  that  of  the  observer  of  planet  and 
star,  the  surgeon  in  much  the  same  way  reasons  from  result  to 
cause.  In  1870  Fritsch  and  Bitzig,  two  German  investigators, 
observed  that  in  applying  an  electric  shock  to  a  well  defined  area 
of  the  brain  of  a  chloroformed  dog,  its  limbs  moved.  One  part 
of  the  brain  thus  excited  would  cause  the  fore-leg  to  twitch,  an- 
other part  would  lead  the  hind-leg  to  move.  When  a  specific  area 
of  the  animal's  brain  was  taken  away,  a  corresponding  part  of  its 
body— the  eyes,  ears,  or  limbs,  were  permanently  paralyzed.  From 
studies  thus  begun  it  has  been  clearly  proved  that  in  the  brain 
of  animals  there  is  a  division  of  labor,  each  activity  being  as 
much  localized  within  the  skull  as  it  is  externally  in  the  nose, 
ears,  or  feet.  The  examination  of  human  victims  of  disease  and 
injury  has  confirmed  all  this.  A  patient  may  have  suffered  loss 
of  power  to  write,  to  speak,  to  stand  firmly  on  his  feet,  for  weeks 
or  months  before  the  end.  The  cause  in  many  cases  is  found  to 
be  a  tumor,  sometimes  no  larger  than  a  pea,  which  has  pressed 
down  upon  a  particular  area  of  the  brain  and  so  given  rise  to  the 
trouble.  A  depressed  fragment  of  bone  in  fracture  of  the  skull 
has  a  similar  effect.  With  these  facts  in  mind,  when  a  surgeon  is 
called  in  to  treat  a  patient  who  is  suffering  from  loss  of  power  to 
write,  speak  or  stand,  he  lifts  the  sufferer's  skull  for  a  small  space 
over  the  specially  indicated  area,  relieving  the  depressed  frac- 
ture, or  exposing  the  small  tumor,  which  he  removes,  usually  with 
restoration  to  health. 

A  generation  ago  much  was  said  about  functional  diseases,  it 
being  supposed  that  apart  from  the  mechanism  of  bone,  muscle  or 
nerve,  the  bodily  functions  might  go  astray  of  themselves.  Im- 
provements in  the  microscope  have  shown  that  many  of  these  de- 


PROFIT  IN  CONTRARIES  379 

rangements  are  due  to  diseases  of  structure ;  and  beyond  the 
range  of  the  microscope  a  careful  study  of  symptoms  enables  the 
physician  to  infer  that  physical  structures  are  affected  in  modes 
which,  one  of  these  days,  he  may  be  able  to  see  and  picture. 

An  eminent  oculist,  Dr.  Casey  A.  Wood  of  Chicago,  tells  me 
that  certain  diseases  of  the  brain  and  kidneys  derange  the  sight 
in  a  way  clearly  revealed  by  an  opthalmoscope,  a  small  instru- 
ment by  which  the  interior  of  the  eye  may  be  explored  through 
the  pupil.  Thus  a  patient  complaining  of  imperfect  vision  may 
be  really  suffering  from  an  ailment  involving  much  more  than 
the  eyes. 

A  noteworthy  group  of  physicians  devote  themselves  to  the 
care  of  the  insane,  that  is,  of  patients  whose  brains  are  diseased. 
As  a  general  rule  when  insanity  declares  itself,  manners  depart 
first,  then  morals,  and  finally  the  physical  powers  of  the  eye,  the 
ear,  the  hand.  All  in  reverse  telling  the  story  of  how  mankind 
became  human ;  first  in  developing  the  faculties  shared  with  bird 
and  beast,  then  -in  rearing  character,  and  at  last,  in  adding  the 
graces  of  behavior. 

From  this  digression  into  matters  of  astronomy  and  of  the 
human  body  and  mind,  let  us  return  to  the  workshop  and  the 
engine-room.    There  is  gain,  as  we  have  seen, 
when   an    inventor   takes   a    familiar   process,  Profit  in 

like  planing,  and  reverses  it,  so  that  instead  of 
the  plane  moving  across  a  board,  the  board  is  moved  beneath  a 
planer.  Not  seldom,  too,  profit  has  followed  upon  adopting  a 
plan  just  the  contrary  of  a  time-honored  practice,  as  when  a 
Frenchman  pierced  a  needle  with  an  eye  near  its  point  instead  of 
away  from  its  point,  taking  a  step  that  did  much  to  make  the  sew- 
ing-machine a  possibility.  Guns  were  loaded  at  the  muzzle  for 
ages,  until  one  day  a  man  of  daring  loaded  them  at  the  breech,  to 
find  that  method  preferable  in  every  way.  A  bullet  or  ball  might 
then  be  larger  and  closer  in  fit  than  before,  have  greater  velocity 
and  penetration,  while  truer  in  flight,  especially  if  sped  from  a 
rifled  gun.  Anvthing  left  in  the  gun  was  in  front  of  the  new 
charge  instead  of  behind  it.  In  manufacture,  the  perishable  parts 
of  the  gun,  its  vent  and  the  adjacent  steel,  are  now  in  a  movable 
breech-piece  where  they  may  be  replaced  with  little  cost  and 


380 


THEORIES 


trouble.  Loading  and  firing  may  be  much  more  rapid  than  with 
muzzle-loaders,  while  less  space  is  required  and  the  gunners  are 
much  less  exposed  than  formerly.  And  ages  before  there  was 
such  a  thing  as  a  firearm,  a  vast  stride  in  tilling  the  ground  was 
taken  simply  by  reversing  an  ancient  practice.  At  first  the  soil 
was  scratched  by  a  stick  drawn  along  its  surface;  when  some 
primeval  Edison  gave  the  stick  a  forward  instead  of  a  backward 
thrust  he  created  the  plow,  and  tillage  began  in  earnest. 

In  feeding  coal  to  a  fire,  as  in  the  case  of  a  common  grate,  the 
one  plan  for  centuries  was  to  add  the  fuel  from  above.  As 
gradually  heated  by  the  glowing  mass  beneath  it,  this  fresh  fuel 
sent  forth  comparatively  cool  gases  which,  to  a  considerable  ex- 
tent, passed  into  the  chimney  without  being  burnt.  A  mechanical 
stoker  of  the  underfeed  type  forces  fresh  coal  beneath  the  fuel 
already  aglow ;  the  result  is  that  all  the  gases  from  the  fresh  coal 
pass  through  an  incandescent  bed  which  heats  them  highly,  so 
that  on  emergence  into  the  air-current  they  are  thoroughly  con- 
sumed. 


Link  Belt  Machinery  Co.'s  Shop,  Chicago, 
showing  Sturtevant  ventilating  and  heating  apparatus. 

In  large  machine  shops  a  heating  system  is  finding  favor  which 
equally  departs  from  traditional  methods.  In  a  small  workshop 
piping  filled  with  steam  or  hot  water  serves  well  enough:  in  a 


FURNACE  INSIDE  BOILER          381 

lofty  machine  shop  it  serves  badly,  sending  as  it  does  warm  cur- 
rents of  air  toward  the  roof  where  warmth  does  only  harm.  The 
union  of  a  fan  with  a  system  of  steam  coils  introduces  a  vast  im- 
provement. Air  warmed  to  any  desired  temperature  is  carried  in 
ducts  throughout  the  building,  with  outlets  at  the  points  most  in 
need  of  heat.  Instead  of  being  allowed  to  take  its  way  to  the 
roof,  the  warmed  air  is  forcibly  directed  to  the  floor  which  other- 
wise would  be  unduly  cool.  Because  the  air  is  in  rapid  motion 
the  heating  coils  may  not  be  more  than  one  fourth  as  extensive 
as  for  a  system  of  direct  radiation.  This  plan  has  the  further  ad- 
vantage of  utilizing  exhaust  steam  without  producing  undue  back 
pressure  on  the  pumps  or  engines,  and  yields  results  almost  equal 
to  those  from  live  steam.  See  accompanying  illustration. 

Lighting  as  well  as  heating  may  share  the  gain  of  changing 
an  old  method  for  its  contrary.  Many  forms  of  reflectors,  both  in 
glass  and  metal,  have  been  designed  to  scatter  the  beams  of  lamps, 
usually  in  a  downward  direction.  An  excellent  plan  directs  the 
positive  carbon  of  an  arc-lamp  to  the  ceiling  instead  of  to  the 
floor;  from  the  ceiling,  duly  whitened,  the  rays  descend  more 
thoroughly  and  agreeably  diffused  than  if  reflected  from  mirrors 
or  refracted  by  prisms,  however  ingeniously  shaped  and  disposed. 
See  illustration  on  page  75. 

In  the  days  of  small  things  in  engineering,  which  ended  only 
with  Watt  and  his  steam  engine,  when  a  kettle  was  to  be  heated 
the  proper  place  for  its  fire  was  thought  to  be  outside.  But  when 
big  boilers  came  in,  with  urgent  need  that  their  contents  be  heated 
with  all  despatch,  it  was  found  gainful  to  put  the  fire  inside. 
Stephenson  owed  no  small  part  of  the  success  of  his  locomotive, 
the  "Rocket,"  to  its  boiler  being  outside  its  flame.  The  most 
efficient  modern  boilers  fully  develop  this  principle. 

In  an  ordinary  furnace  the  draft  moves  upward,  obeying  the 
impulse  due  to  the  lightness  of  its  heated  gases.  This  direction 
is  reversed  in  down-draft  furnaces  which  were  originally  devised 
by  Lord  Dundonald  more  than  a  century  ago.  In  their  modern 
types  a  fan  blast  forces  the  draft  downward  through  the  fuel, 
with  the  effect  that  the  p-pses  3  re  so  intenselv  heated  as  to  be 
thoroughlv  burned.  The  grate-bars  are  of  water-tube,  connected 
to  the  boiler  as  part  and  parcel  of  its  heating  surface.  In  the 


382 


THEORIES 


Loomrs  gas-producer  a  like  method  is  adopted  :.the  fuel  is  charged 
through  an  open  door  in  the  top  of  the  generator  and  the  gas  is 
exhausted  from  the  bottom  of  the  fire.  Thus  all  tarry  and 
volatile  matter  in  bituminous  coal  or  wood  is  converted  into  a 
fixed  gas. 

Thirty  years  ago  one  would  have  supposed  the  wheels  of  ordi- 
nary carts  and  carriages  to  be  safe  from  change,  to  be  among  the 

heirlooms  secure  of  transmission  to 
posterity.  Not  so.  Observe  the  wheel 
of  a  bicycle  and  note  that  instead  of 
stout  spokes  upholding  the  hub,  there 
are  thin  steel  wires  from  which  the 
hub  is  suspended.  Thus  strength  is 
gained  while  the  wheel  is  lightened 
and  material  economized.  Wheels  of 
like  model  are  now  used  in  many 
other  vehicles  where  lightness  is 
particularly  desired.  This  plan  of 
using  spokes  in  tension  instead  of  in 
compression  is  credited  to  Leonardo 
da  Vinci  who  flourished  four  centuries 


Bicycle    wheel    sus- 
pended from  axle 
by  wires. 


ago. 


Judgment  in 

Theorizing : 

Rules  Have 

Limits. 


While  the  men  who  add  to  known  truth,  whether  in  the  realm 
of  matter  or  of  mind,  must  build  on  acquired  knowledge,  they  do 
so  with  common  sense,  by  exercise  of  the 
supreme  faculty  of  judgment.  To  begin  with, 
they  perceive  that  every  force  acts  within  lim- 
its, acts  concurrently  with  other  forces  which 
modify  its  effects.  Speaking  of  gravity  Pro- 
fessor William  James  says:— "A  pendulum  may  be  deflected  by 
a  single  blow  and  swing  back.  Will  it  swing  back  the  more  often, 
the  more  we  multiply  the  blows?  No.  For  if  they  rain  upon  the 
pendulum  too  fast  it  will  not  swing  at  all,  but  remain  deflected  in 
a  sensibly  stationary  state.  Increasing  the  cause  numerically 
need  not  increase  numerically  the  effect.  Blow  through  a  tube ; 
you  get  a  certain  musical  note;  and  increasing  the  blowing  in- 
creases for  a  certain  time  the  loudness  of  the  note.  Will  this  be 
true  indefinitely?  No;  for  when  a  certain  force  is  reached,  the 


OVER-SIMPLIFICATION  383 

note,  instead  of  growing  louder,  suddenly  disappears  and  is  re- 
placed by  its  higher  octave.  Turn  on  the  gas  slightly  and  light 
it;  you  get  a  tiny  flame.  Turn  on  more  gas  and  the  flame  in- 
creases. Will  this  relation  increase  indefinitely  ?  No,  again ;  for 
at  a  certain  moment  up  shoots  the  flame  into  a  ragged  streamer 
and  begins  to  hiss." 

In  a  spirit  as  judicial  Sir  William  Anderson  has  said :— 'There 
is  a  tendency  among  the  young  and  inexperienced  to  put  blind 
faith  in  formulae,  forgetting  that  most  of  them  are  based  upon 
premises  which  are  not  accurately  reproduced  in  practice,  and 
which  in  many  cases  are  unable  to  take  into  account  collateral  dis- 
turbances, which  only  experience  can  foresee,  and  common  sense 
guard  against." 

That,  with  regard  to  a  new  machine,  all  the  facts  of  construc- 
tive and  working  cost  should  be  in  view,  and  after  tests  in  prac- 
tice, is  the  conviction  of  Professor  A.  B.  W. 
Kennedy :- "Machines  cannot  be  finally  criti-        Do  Not  Pay 
cized,  pronounced  good  or  bad,  simply  from       ^ent-ffor  *a  ° 
results  measurable  in  a  laboratory.  One  wishes  Dollar, 

to  use  a  steam  plant,  for  example,  by  which  as 
little  coal  shall  be  burnt  as  possible.  But  clearly  it  would  be 
worth  while  to  waste  a  certain  amount  of  coal  if  a  less  economical 
machine  would  allow  a  larger  saving  in  the  cost  of  repairs  or  of 
interest.  Or,  it  might  be  worth  while  to  use  a  machine  in  which 
a  certain  amount  of  extra  power  was  obviously  employed,  if  only 
by  means  of  such  a  machine  the  cost  of  attendance  could  be  meas- 
urably reduced.  The  'worth-whileness'  of  economies  comes  out 
only  in  practical  experience.  A  careful  training  in  comparatively 
simple  parts  fits  a  man  more  than  anything  else  to  gauge  accu- 
rately the  importance  of  such  parts  as  those  named.  No  doubt 
there  are  many  men  in  whom  the  critical  faculty  is  insufficiently 
developed  to  allow  them  ever  to  be  of  use  in  these  matters,  but  to 
those  who  are  intellectually  capable  of  'the  higher  criticism*  it  is 
of  inestimable  value  to  have  had  a  systematic  training  in  the 
lower." 

To  the  same  effect  are  remarks  by  Professor  J.  Hopkinson  :— 
"Doubling  the  thickness  of  a  cylinder  by  no  means  doubles  its 
strength.  Conversely,  doubling  the  strength  of  the  material  will 


384  THEORIES 

permit  the  thickness  to  be  diminished  to  much  less  than  one  half. 
Until  1869  hydraulic  presses  were  mostly  made  of  cast  iron. 
There  was  much  astonishment  at  the  great  reduction  in  thickness 
and  weight  which  became  possible  when  steel  was  substituted  for 
the  weaker  material.  In  the  case  of  guns  it  is  well-known  that 
greater  strength  can  be  obtained  if  the  outer  hoops  are  shrunken 
on  the  inner  ones.  Mathematical  theory  tells  us  what  amount  of 
shrinkage  should  give  the  best  results.  A  gun  may  have  a  shrink- 
age so  great  as  to  weaken  it." 

He  continues : — "Mathematical  treatment  of  any  problem  is  al- 
ways analytical — attention  is  concentrated  upon  certain  facts,  and 
for  the  moment  other  facts  are  neglected.  For  example,  in  deal- 
ing with  the  thermodynamics  of  the  steam  engine,  one  dismisses 
from  consideration  very  vital  points  essential  to  the  successful 
working  of  the  engine— questions  of  strength  of  parts,  lubrica- 
tion, convenience  for  repairs.  But  if  an  engineer  is  to  succeed  he 
must  not  fail  to  consider  every  element  necessary  to  success;  he 
must  have  a  practical  instinct  which  will  tell  him  whether  the 
engine  as  a  whole  will  succeed.  His  mind  must  not  be  only 
analytical,  or  he  will  be  in  danger  of  solving  bits  of  the  problems 
which  his  work  presents,  and  of  falling  into  fatal  mistakes  on 
points  which  he  has  omitted  to  consider,  and  which  the  plainest, 
intelligent,  practical  man  would  avoid  almost  without  knowing  it. 
Again,  the  powers  of  the  strongest  mathematician  being  limited, 
there  is  a  constant  temptation  to  fit  the  facts  to  suit  the  mathe- 
matics, and  to  assume  that  the  conclusions  will  have  greater  accu- 
racy than  the  premises  from  which  they  are  deduced.  This  is  a 
trouble  one  meets  with  in  other  applications  of  mathematics  to 
experimental  science.  In  order  to  make  the  subject  amenable  to 
treatment,  one  finds,  for  example,  in  the  science  of  magnetism, 
that  it  is  boldly  assumed  that  the  magnetization  of  magnetizable 
material  is  proportionate  to  the  magnetizing  force,  and  the  ratio 
has  a  name  given  to  it,  and  conclusions  are  drawn  from  the  as- 
sumption; but  the  fact  is,  no  such  proportionality  exists,  and  all 
conclusions  resulting  from  the  assumption  are  so  far  invalid. 
Whenever  possible  the  mathematical  deductions  should  be  fre- 
quently verified  by  reference  to  observation  and  experiment,  for 
the  very  simple  reason  that  they  are  only  deductions,  and  the 


JUDGMENT  385 

premises  from  which  the  deductions  are  drawn  may  be  inaccurate 
or  incomplete.  We  must  always  remember  that  we  cannot  get 
more  out  of  the  mathematical  mill  than  we  put  into  it,  though  we 
may  get  it  in  a  form  infinitely  more  useful  for  our  purpose." 

Professor  Alexander  Bain  in  his  "Senses  and  the  Intellect" 
concludes: — "A  sound  judgment,  meaning  a  clear  and  precise 
perception  of  what  is  really  effected  by  the  contrivances  employed, 
is  to  be  looked  upon  as  the  first  requisite  of  the  practical  man. 
He  may  be  meagre  in  intellectual  resources,  he  may  be  slow  in 
getting  forward  and  putting  together  the  appropriate  devices,  but 
if  his  perception  of  the  end  is  unfaltering  and  strong,  he  will  do 
no  mischief  and  practice  no  quackery.  He  may  have  to  wait  long 
in  order  to  bring  together  the  apposite  machinery,  but  when  he 
has  done  so  to  the  satisfaction  of  his  own  thorough  judgment,  the 
success  will  be  above  dispute.  Judgment  is  in  general  more  im- 
portant than  fertility;  because  a  man  by  consulting  others  and 
studying  what  has  been  already  done,  may  usually  obtain  sug- 
gestions enough,  but  if  his  judgment  of  the  end  is  loose,  the 
highest  exuberance  of  intellect  is  only  a  snare." 

As  applied  science  rises  to  higher  and  higher  planes,  a  good 
many  questions  which  were  once  matters  of  judgment,  become 
subjects  of  estimate,  often  precise.    A  century 
ago  the  forms  of  ships  were  decided  by  sheer   judgment  Moves 
sagacity ;  to-day,  as  we  have  seen  in  this  book,      to  New  Fields, 
such  forms  are  of  definite  approved  types,  each 
adapted  to  specific  needs,  and  never  departed  from  by  a  prudent 
designer  except  in  slight  and  carefully  noted  variations.     Such 
examples  may  be  drawn  from  many  another  field  where  science 
and  industry  join  hands,  especially  in  every  branch  of  modern 
engineering.      A  new  power-plant,  in  every  detail  of  its  installa- 
tion, is  so  standardized  that  a  competent  corps  of  erectors,  from 
any  part  of  the  civilized  w«rld,  can  readily  put  it  together.     Its 
designers  from  first  to  last  have  sought  to  make  operation  easy, 
and  every  working  part  "fool-proof."     In  case  of  accident  any 
item  of  the  structure  broken  or  deranged  can  be  supplied  by  the 
builders  at  once. 

All  this  does  not  mean  that  science  in  its  onward  march  is 
eliminating  the  need  for  judgment,  but  simply  that  judgment  is 


386  THEORIES 

constantly  passing  into  territory  wholly  new.  In  devising  gas- 
engines  of  novel  principle,  in  combining  chemicals  for  new 
economies  of  illumination,  the  faculty  of  judgment  enters  provinces 
vastly  broader  than  those  from  which  it  has  retired  as  its  ap- 
proximations have  given  place  to  exact  measurements.  Manual 
skill  has  of  late  undergone  a  similar  change  of  scope.  Many  a 
modern  machine  performs  hammering,  punching,  riveting  more 
effectively  and  swiftly  than  human  hands,  so  that  here  an  operator 
of  little  skill  replaces  a  mechanic  of  much  skill.  But  in  another 
and  higher  field,  deftness  was  never  more  in  request  than  to-day. 
In  the  final  adjustments  of  a  voltmeter,  of  a  refractometer,  in  the 
last  polish  given  to  an  observatory  lens,  a  delicacy  of  touch  is 
demanded  compared  with  which  the  dexterity  of  an  old-time 
planisher  or  file-grinder  is  mere  clumsiness. 


CHAPTER  XXVI 
NEWTON,  FARADAY  AND  BELL  AT  WORK 

Newton,  the  supreme  generalizer  .  .  .  Faraday,  the  master  of  experiment 
.  .  .  Bell,  the  inventor  of  the  telephone,  transmits  speech  by  a  beam 
of  light. 

HAVING  now  taken  a  rapid  general  view  of  observation  and 
experiment,  of  the  faculty  of  sound  theorizing,  let  us  enter 
the  presence  of  two  great  masters  of  research  and  invention,  be- 
ginning with  a  man  who  united  the  loftiest  powers  as  a  mathema- 
tician, a  physicist,  and  a  generalizer. 

How  Sir  Isaac  Newton  discovered  the  law  of  gravitation  is 
thus  told  in  his  Life  by  Sir  David  Brewster :— "It  was  either  in 
1665  or   1666  that  Newton's  mind  was  first 
directed  to  the  subject  of  gravity.    He  appears       How  Newton 

t  ,     e         r*         \      •  1  •  e  Discovered  the 

to    have    left    Cambridge    some    time    before  Law  oj. 

August  8,  1665,  when  the  college  was  dis-  Gravitation. 
missed  on  account  of  the  plague,  and  it  was, 
therefore,  in  the  autumn  of  that  year,  and  not  in  that  of  1666,  that 
the  apple  is  said  to  have  fallen  from  the  tree  at  Woolsthorpe,  and 
suggested  to  Newton  the  idea  of  gravity.  When  sitting  alone  in 
the  garden,  and  speculating  on  the  power  of  gravity,  it  occurred 
to  him  that,  as  the  same  power  by  which  the  apple  fell  to  the 
ground  was  not  sensibly  diminished  at  the  greatest  distance  from 
the  centre  of  the  earth  to  which  we  can  reach,  neither  at  the  sum- 
mits of  the  loftiest  spires,  nor  on  the  tops  of  the  highest  moun- 
tains, it  might  extend  to  the  moon  and  retain  her  in  her  orbit,  in 
the  same  manner  as  it  bends  into  a  curve  the  path  of  a  stone  or 
a  cannon  ball,  when  projected  in  a  straight  line  from  the  surface 
of  the  earth.  If  the  moon  was  thus  kept  in  her  orbit  by  gravita- 
tion, or,  in  other  words,  its  attraction,  it  was  equally  probable,  he 
thought,  that  the  planets  were  kept  in  their  orbits  by  gravitating 


388  SIR  ISAAC  NEWTON 

towards  the  sun.  Kepler  had  discovered  the  great  law  of  the 
planetary  motions,  that  the  squares  of  their  periodic  times  were 
as  the  cubes  of  their  distances  from  the  sun,  and  hence  Newton 
drew  .the  important  conclusion  that  the  force  of  gravity,  or  attrac- 
tion, by  which  the  planets  were  retained  in  their  orbits,  varied 
as  the  square  of  their  distances  from  the  sun.  Knowing  the  force 
of  gravity  at  the  earth's  surface,  he  was,  therefore,  led  to  com- 
pare it  with  the  force  exhibited  in  the  actual  motion  of  the  moon, 
in  a  circular  orbit;  but  having  assumed  that  the  distance  of  the 
moon  from  the  earth  was  equal  to  sixty  of  the  earth's  semi-di- 
ameters, he  found  that  the  force  by  which  the  moon  was  drawn 
from  its  rectilinear  path  in  a  second  of  time  was  only  13.9  feet, 
whereas  at  the  surface  of  the  earth  it  was  16.1  in  a  second.  This 
great  discrepancy  between  his  theory  and  what  he  then  considered 
to  be  the  fact,  induced  him  to  abandon  the  subject,  and  pursue 
other  studies  with  which  he  had  been  occupied. 

"It  does  not  distinctly  appear  at  what  time  Newton  became 
acquainted  with  the  more  accurate  measurement  of  the  earth, 
executed  by  Picard  in  1670,  and  was  thus  led  to  resume  his  in- 
vestigations. Picard's  method  of  measuring  his  degree,  and  the 
precise  result  which  he  obtained,  were  communicated  to  the  Royal 
Society,  January  n,  1672,  and  the  results  of  his  observations  and 
calculations  were  published  in  the  Philosophical  Transactions  for 
1675.  But  whatever  was  the  time  when  Newton  became  ac- 
quainted with  Picard's  measurement,  it  seems  to  be  quite  certain 
that  he  did  not  resume  his  former  thoughts  concerning  the  moon 
until  1684.  Pemberton  tells  us,  that  'some  years  after  he  laid 
aside'  his  former  thoughts,  a  letter  from  Dr.  Hooke  put  him  on 
inquiring  what  was  the  real  figure  in  which  a  body,  let  fall  from 
any  high  place,  descends,  taking  the  motion  of  the  earth  round  its 
axis  into  consideration,  and  that  this  gave  occasion  to  his  resuming 
his  former  thoughts  concerning  the  moon,  and  determining,  from 
Picard's  recent  measures,  that  'the  moon  appeared  to  be  kept  in 
her  orbit  purely  by  the  power  of  gravity.'  But  though  Hooke's 
letter  of  1679  was  the  occasion  of  Newton's  resuming  his  inquiries, 
it  does  not  fix  the  time  when  he  employed  the  measures  of 
Picard.  In  a  letter  from  Newton  to  Halley,  in  1686,  he  tells  him 
that  Hooke's  letters  in  1679  were  tne  cause  of  his  'finding  the 


THE  LAW  OF  GRAVITATION         389 

method  of  determining  the  figures,  which,  when  I  had  tried  in 
the  ellipsis,  I  threw  the  calculations  by,  being  upon  other  studies : 
and  so  it  rested  for  about  five  years,  till,  upon  your  request,  1 
sought  for  the  papers/  Hence  Mr.  Rigaud  considers  it  clear,  that 
the  figures  here  alluded  to  were  the  paths  of  bodies  acted  upon 
by  a  central  force,  and  that  the  same  occasion  induced  him  to 
resume  his  former  thoughts  concerning  the  moon,  and  to  avail 
himself  of  Picard's  measures  to  correct  his  calculations.  It  was, 
therefore,  in  1684,  that  Newton  discovered  that  the  moon's  de- 
flection in  a  minute  was  sixteen  feet,  the  same  as  that  of  bodies 
at  the  earth's  surface.  As  his  calculations  drew  to  a  close,  he  is 
said  to  have  been  so  agitated  that  he  was  obliged  to  desire  a 
friend  to  finish  them." 

With  no  mathematics  beyond  simple  arithmetic,  Michael  Far- 
aday displayed  powers  of  experiment  and  generalization  so  ex- 
traordinary that  in  these  respects  he  stands  at 
the  same  height  as  Newton  himself.     In  the  Michael 

life  of  Michael  Faraday,  by  Dr.  J.  H.  Glad-          Method^ 
stone,  we  are  given  his  account  of  the  great          Working, 
physicist's  method  of  working:— 

"The  habit  of  Faraday  was  to  think  out  carefully  beforehand 
the  subject  on  which  he  was  working,  and  to  plan  his  mode  of 
attack.  Then,  if  he  saw  that  some  new  piece  of  apparatus  was 
needed,  he  would  describe  it  fully  to  the  instrument  maker  with  a 
drawing,  and  it  rarely  happened  that  there  was  any  need  of 
alteration  in  executing  the  order.  If,  however,  the  means  of  ex- 
periment existed  already  4  he  would  give  Anderson,  his  assistant, 
a  written  list  of  the  things  he  would  require,  at  least  a  day  before 
—  for  Anderson  was  not  to  be  hurried.  When  all  was  ready,  he 
would  descend  into  the  laboratory,  give  a  quick  glance  round  to 
see  that  all  was  right,  take  an  apron  from  the  drawer,  and  rub 
his  hands  together  as  he  looked  at  the  preparations  made  for  his 
work.  There  must  be  no  tool  on  the  table  but  such  as  he  re- 
quired. As  he  began  his  face  would  be  exceedingly  grave,  and 
during  the  progress  of  an  experiment  all  must  be  exceedingly 
quiet;  but  if  it  was  proceeding  according  to  his  wish,  he  would 
commence  to  hum  a  tune,  and  sometimes  to  rock  himself  side- 
ways, balancing  alternately  on  either  foot.  Then,  too,  he  would 


390  MICHAEL  FARADAY 

often  talk  to  his  assistant  about  the  result  he  was  expecting.  He 
would  put  away  each  tool  in  its  own  place  as  soon  as  done  with, 
or  at  any  rate  as  soon  as  the  day's  work  was  over,  and  he  would 
not  unnecessarily  take  a  thing  away  from  its  place.  No  bottle 
was  allowed  to  remain  without  its  proper  stopper ;  no  open  glass 
might  stand  for  a  night  without  a  paper  cover ;  no  rubbish  was  to 
be  left  on  the  floor;  bad  smells  were  to  be  avoided  if  possible;  and 
machinery  in  motion  was  not  to  be  permitted  to  grate.  In  work- 
ing, also,  he  was  very  careful  not  to  employ  more  force  than  was 
wanted  to  produce  the  effect.  When  his  experiments  were  fin- 
ished and  put  away,  he  would  leave  the  laboratory,  and  think 
further  about  them  upstairs. 

"It  was  through  this  lifelong  series  of  experiments  that  Far- 
aday won  his  knowledge  and  mastered  the  forces  of  nature.  The 
rare  ingenuity  of  his  mind  was  ably  seconded  by  his  manipula- 
tive skill,  while  the  quickness  of  his  perceptions  was  equalled  by 
the  calm  rapidity  of  his  movements.  He  had  indeed  a  passion  for 
experimenting.  This  peeps  out  in  the  preface  to  the  second  edi- 
tion of  his  'Chemical  Manipulation/  where  he  writes,  'Being  in- 
tended especially  as  a  book  of  instruction,  no  attempts  were  made 
to  render  it  pleasing,  otherwise  than  by  rendering  it  effectual ;  for 
I  concluded  that,  if  the  work  taught  clearly  what  it  was  intended 
to  inculcate,  the  high  interest  always  belonging  to  a  well-made  or 
successful  experiment  would  be  sufficient  to  give  it  all  the  re- 
quisite charms,  and  more  than  enough  to  make  it  valuable  in  the 
eyes  of  those  for  whom  it  was  designed/ 

"He  could  scarcely  pass  a  gold  leaf  electrometer  without 
causing  the  leaves  to  diverge  by  a  sudden  flick  from  his  silk  hand- 
kerchief. I  recollect,  too,  his  meeting  me  at  the  entrance  to  the 
lecture  theatre  at  Jermyn  Street,  when  Lyon  Play  fair  was  giving 
the  first,  or  one  of  the  first  lectures  ever  delivered  in  the  building. 
'Let  us  go  up  here/  said  he,  leading  me  far  away  from  the  central 
table.  I  asked  him  why  he  chose  such  an  out-of-the-way  place. 
'Oh/  he  replied,  'we  shall  be  able  here  to  find  out  what  are  the 
acoustic  qualities  of  the  room/ 

"The  simplicity  of  the  means  with  which  he  made  his  experi- 
ments was  often  astonishing,  and  was  indeed  one  of  the  mani- 
festations of  his  genius.  A  good  instance  is  thus  narrated  by  Sir 


SIMPLE  MEANS  OF  EXPERIMENT  391 

Frederick  Arrow:— 'When  the  electric  light  was  first  permanently 
exhibited  at  Dungeness,  on  6th  June,  1862,  a  committee  of  the 
Elder  Brethren,  of  which  I  was  one,  accompanied  Faraday  to 
observe  it.  Before  we  left  Dover,  Faraday  showed  me  a  little 
common  paper  box  and  said,  "I  must  take  care  of  this ;  it  's  my 
special  photometer," — and  then,  opening  it,  produced  a  lady's  or- 
dinary black  shawl  pin  (jet,  or  imitation,  perhaps)— and  then 
holding  it  a  little  way  off  the  candle,  showed  me  the  image  very 
distinct ;  and  then,  putting  it  a  little  further  off,  placed  another 
candle  near  it,  and  the  relative  distance  was  shown  by  the  size  of 
the  image/ 

"In  lecturing  to  the  young  he  delighted  to  show  how  easily 
apparatus  might  be  extemporized.  Thus,  in  order  to  construct 
an  electrical  machine,  he  once  inverted  a  four-legged  stool  to 
serve  for  the  stand,  and  took  a  white  glass  bottle  for  the  cylinder. 
A  cork  was  fastened  into  the  mouth  of  this  bottle,  and  a  bung  was 
fastened  with  sealing  wax  to  the  other  end :  into  the  cork  was  in- 
serted a  handle  for  rotating  the  bottle,  and  in  the  centre  of  the 
bung  was  a  wooden  pivot  on  which  it  turned :  while  with  some 
stout  wire  he  made  crutches  on  two  of  the  legs  of  the  stool  for 
the  axles  of  this  glass  cylinder  to  work  upon.  The  silk  rubber 
he  held  in  his  hand.  A  japanned  tea  cannister  resting  on  a  glass 
tumbler  formed  the  conductor,  and  the  collector  was  the  head  of 
a  toasting  fork.  With  this  apparently  rough  apparatus  he  ex- 
hibited all  the  rudimentary  experiments  in  electricity  to  a  large 
audience." 

Faraday,  in  addition  to  the  rarest  ability  in  experiment,  had  an 
orderliness  of  mind  which  gave  the  utmost  effectiveness  to  his 
work    in    every    department.      His    successor, 
Professor  John  Tyndall,  says :-  Faraday's 

"Faraday's  sense  of  order  ran  like  a  lu- 
minous  beam  through  all  the  transactions  of  his 
life.  The  most  entangled  and  complicated  matters  fell  into  har- 
mony in  his  hands.  His  mode  of  keeping  accounts  excited  the 
admiration  of  the  managing  board  of  the  Royal  Institution.  And 
his  science  was  similarly  ordered.  In  his  Experimental  Re- 
searches he  numbered  every  paragraph,  and  welded  their  various 
parts  together  by  incessant  reference.  His  private  notes  of  the 


392  MICHAEL  FARADAY 

Experimental  Researches  which  are  happily  preserved,  are 
similarly  numbered;  their  last  paragraph  bears  the  number  16,041. 
His  working  qualities,  moreover,  showed  the  tenacity  of  the 
Teuton.  His  nature  was  impulsive,  but  there  was  a  force  behind 
the  impulse  which  did  not  permit  it  to  retreat.  If  in  his  warm 
moments  he  formed  a  resolution,  in  his  cool  ones  he  made  that 
resolution  good.  Thus  his  fire  was  that  of  a  solid  combustible, 
not  that  of  a  gas,  which  blazes  suddenly,  and  dies  as  suddenly 
away." 

Faraday  had  exalted  powers  of  imagination  and  as  he  gazed  at 
the  curves  in  which  iron-filings  disposed  themselves  when  tapped 
on  a  card  held  above  a  magnet,  he  saw  similar  "lines  of  force" 
surrounding  every  attracting  mass  of  whatever  kind.  Other  ob- 
servers had  confined  their  attention  to  what  takes  place,  or  is 
supposed  to  take  place,  in  a  conductor;  he  closely  scanned  what 
took  place  around  a  conductor.  He  was  thus  addressed  in  a  letter 
from  that  remarkable  physicist,  Professor  James  Clerk  Maxwell 
of  Cambridge  :— 

"As  far  as  I  know  you  are  the  first  person  in  whom  the  idea  of 
bodies  acting  at  a  distance  by  throwing  the  surrounding  medium 
into  a  state  of  constraint  has  arisen,  as  a  principle  to  be  actually 
believed  in.  We  have  had  streams  of  hooks  and  eyes  flying 
around  magnets,  and  even  pictures  of  them  so  beset;  but  nothing 
is  clearer  than  your  description  of  all  sources  of  force  keeping  up 
a  state  of  energy  in  all  that  surrounds  them,  which  state  by  its  in- 
crease or  diminution  measures  the  work  done  by  any  change  in 
the  system.  You  seem  to  see  the  lines  of  force  curving  round  ob- 
stacles and  driving  plump  at  conductors,  and  swerving  toward 
certain  directions  in  crystals,  and  carrying  with  them  everywhere 
the  same  amount  of  attractive  power,  spread  wider  or  denser  as 
the  lines  widen  or  contract.  You  have  seen  that  the  great  mystery 
is,  not  how  like  bodies  repel  and  unlike  attract,  but  how  like  bodies 
attract  by  gravitation.  But  if  you  can  get  over  that  difficulty 
either  by  making  gravity  the  residual  of  the  two  electricities  or 
by  simply  admitting  it,  then  your  lines  of  force  can  'weave  a  web 
across  the  sky/  and  lead  the  stars  in  their  courses  without  any 
necessarily  immediate  connection  with  the  objects  of  their  at- 
traction. ." 


LIGHT  A  CARRIER  OF  SPEECH     393 

Michael  Faraday,  as  we  have  seen,  by  researches  of  consum- 
mate ability  laid  the  foundation  of  modern  electrical  science  and 
art.  In  that  field  there  is  to-day  no  inventor 
more  illustrious  than  Professor  Alexander  How  Li£ht 
Graham  Bell,  the  creator  of  the  telephone,  that 
simplest  and  mdst  important  of  electrical  de- 
vices.1 Not  content  with  obliging  a  wire  to  carry  speech  in  elec- 
tric waves,  Professor  Bell  has  impressed  beams  of  light  into  the 
same  service.  The  successive  steps  by  which  he  arrived  at  the 
photophone  are  of  extraordinary  interest.  His  story  as  given  in 
the  proceedings  of  the  American  Association  for  the  Advance- 
ment of  Science,  1880,  is  here  somewhat  condensed  :— 

"In  bringing  before  you  some  discoveries  by  Mr.  Sumner 
Tainter  and  myself,  which  have  resulted  in  the  production  and 
reproduction  of  sound  by  means  of  light,  let  me  sketch  the  state 
of  knowledge  which  formed  the  starting  point  of  our  experi- 
ments. I  shall  first  describe  selenium,  and  the  uses  of  it  devised 
by  previous  expeiimenters ;  our  researches  have  so  widened  the 
class  of  substances  sensitive,  like  selenium,  to  light-vibrations 
that  this  sensitiveness  seems  to  be  a  property  of  all  matter.  We 
have  found  this  property  in  gold,  silver,  platinum,  iron,  steel, 
brass,  copper,  zinc,  lead,  antimony,  german-silver,  ivory,  celluloid, 
gutta  percha,  hard  and  soft  rubber,  paper,  parchment,  wood,  mica, 
and  silvered  glass.  At  first  carbon  and  microscope  glass  seemed 
insensitive ;  later  experiments  proved  them  to  be  no  exceptions  to 
the  rule. 

"We  find  that  when  a  vibratory  beam  of  light  falls  upon  these 
substances  they  emit  sounds,  the  pitch  of  which  depends  upon 
the  frequency  of  the  vibratory  change  in  the  light.  We  also  find 
that  when  we  control  the  form  or  character  of  the  light-vibrations, 
we  control  the  quality  of  the  sound,  and  obtain  all  varieties  of 

1  Professor  Bell's  narrative  of  how  he  invented  the  telephone  is  given  in 
"Invention  and  Discovery,"  one  of  the  six  volumes  of  "Little  Masterpieces 
of  Science,"  Doubleday,  Page  &  Co.,  New  York.  In  "Flame,  Electricity 
and  the  Camera"  by  the  present  writer,  published  by  the  same  firm,  is  a 
chapter  describing  the  telephone  in  its  later  developments.  This  chapter 
was  revised  by  the  late  Professor  Alexander  Melville  Bell,  father  of  the 
inventor. 


394    ALEXANDER  GRAHAM  BELL 

articulate  speech.  We  can  thus  speak  from  station  to  station 
wherever  we  can  project  a  beam  of  light.  Selenium,  indispensable 
in  the  apparatus,  was  discovered  by  Berzelius  in  1817.  It  is  a 
metalloid  resembling  tellurium ;  they  differ,  however,  in  electrical 
properties;  tellurium  is  a  good  conductor,  selenium  in  its  usual 
forms  is  a  non-conductor.  Knox,  in  1837,  discovered  that  selenium 
is  a  conductor  when  fused;  in -1851,  Hittorf  showed  that  it  con- 
ducts when  in  one  of  its  allotropic  forms.  When  selenium  is 
rapidly  cooled  from  a  fused  condition  it  is  a  non-conductor.  In 
this  vitreous  form  it  is  dark  brown,  almost  black  by  reflected  light, 
having  an  exceedingly  brilliant  surface;  in  thin  films  it  is  trans- 
parent, and  appears  of  a  beautiful  ruby  red  by  transmitted  light. 
When  selenium  is  cooled  from  fusion  with  extreme  slowness,  it 
presents  an  entirely  different  appearance,  being  of  a  dull  lead 
color,  and  having  throughout  a  granular  or  crystalline  structure 
and  looking  like  a  metal.  It  is  now  opaque  even  in  very  thin 
films.  It  was  this  kind  of  selenium  that  Hittorf  found  to  be  a 
conductor  of  electricity  at  ordinary  temperatures.  He  also  noticed 
that  its  resistance  to  the  passage  of  electricity  diminished  con- 
tinuously by  heating  up  to  the  point  of  fusion ;  and  that  the  resist- 
ance suddenly  increased  as  the  solid  passed  to  liquidity.  It  was 
early  discovered  that  exposure  to  sunlight  hastens  the  change  of 
selenium  from  one  allotropic  form  to  another;  an  observation  of 
significance  in  the  light  of  recent  discoveries. 

"Mr.  Willoughby  Smith,  an  engineer  engaged  in  the  laying  of 

submarine  cables,  had  devised  a  system  of  testing  and  signalling 

during  their  submersion.     For  this  system,  in 

The  Cardinal         ^     {i  occurre(j  to  him  that  he  might  employ 
Discovery.  «•  •  r  .      .  .    , 

crystalline  selenium,  on  account  of  its  high  re- 
sistance, at  the  shore  end  of  a  cable.  On  experiment  the  selenium 
was  found  to  have  all  the  resistance  required;  some  of  the  bars 
displayed  a  resistance  of  1400  megohms,  as  much  as  would  be 
offered  by  a  telegraph  wire  long  enough  to  reach  from  the  earth 
to  the  sun.  But  this  resistance  was  found  to  be  extremely  vari- 
able; the  reason  was  disclosed  when  Mr.  May,  an  assistant,  ob- 
served that  the  resistance  of  selenium  is  less  in  light  than  in 
darkness.  This  discovery  created  widespread  interest  through- 
out the  world.  Among  the  investigators  who  at  once  turned  their 


AID  FROM  THE  TELEPHONE      395 

attention  to  the  subject  was  Professor  W.  G.  Adams  of  King's 
College,  London,  who  proved  that  the  action  on  selenium  is 
chiefly  due  to  the  luminous  rays  of  the  spectrum,  the  ultra-red 
and  ultra-violet  rays  having  little  or  no  effect.  Dr.  Werner 
Siemens,  the  eminent  German  physicist,  produced  a  variety  of 
selenium  fifteen  times  more  conductive  in  sunlight  than  in  dark- 
ness. This  extraordinary  sensitiveness  was  brought  about  by 
heating  for  some  hours  at  a  temperature  of  210°  C,  followed  by 
extremely  slow  cooling. 

"Observations  concerning  the  effect  of  light  upon   the  con- 
ductivity of  selenium  had  employed  the  galvanometer  solely;  it 
occurred  to  me  that  the  telephone,   from  its 
extreme    sensitiveness,    might    be    substituted       The  Telephone 
with  advantage.     On  consideration  I  saw  that         Brought  in. 
the  experiments  could  not  be  conducted  in  the 
ordinary  way  with  continuous  light,  for  a  good  reason :  the  law 
of  audibility  of  the  telephone  is  precisely  analogous  to  the  law  of 
electrical  induction.    No  effect  is  produced  during  the  passage  of 
a  continuous  and  steady  current.     It  is  only  at  the  moment  of 


Telephones  receiving  sounds  through  a  beam  of  light. 


change  from  a  stronger  to  a  weaker  state,  or,  vice  versa,  that  any 
audible  effect  is  produced;  this  effect  is  exactly  proportional  to 
the  amount  of  variation  in  the  current.  It  was,  therefore,  evident 
that  the  telephone  could  only  respond  to  the  effect  produced  in 


396   ALEXANDER  GRAHAM  BELL 

selenium  at  the  moment  of  change  from  light  towards  darkness, 
or  vice  versa,  and  that  it  would  be  advisable  to  intermit  the  light 
with  great  rapidity  so  as  to  produce  a  succession  of  changes  in 
the  conductivity  of  the  selenium  corresponding  in  frequency  to 
musical  vibrations  within  the  limits  of  the  sense  of  hearing.  For 
I  had  often  noticed  that  currents  of  electricity,  so  feeble  as  hardly 
to  produce  any  audible  effects  from  a  telephone  when  the  circuit 
was  simply  opened  and  closed,  caused  very  perceptible  musical 
sounds  when  the  circuit  was  rapidly  interrupted;  and  that  the 
higher  the  pitch  of  the  sound  the  more  audible  was  its  effect.  I 
was  much  struck  by  the  idea  of  producing  sound  in  this  way  by 
the  action  of  light.  Accordingly  I  proposed  to  pass  a  bright 
light  through  one  of  the  orifices  in  a  perforated  screen  consisting 
of  a  circular  disk  with  holes  near  its  circumference.  Upon  rapidly 
rotating  the  disk  an  intermittent  beam  of  light  would  fall  on  the 
selenium,  and  from  a  connected  telephone  a  musical  tone  would 
be  produced,  its  pitch  depending  upon  the  rapidity  with  which 
the  disk  spun  round. 

"Upon  further  consideration  I  saw  that  the  effect  could  not 

only  be  produced  at  the  extreme  distance  at  which  selenium  would 

normally  respond  to  the  action  of  a  luminous 

Variations  of  body,  but  that  this  distance  could  be  indefinitely 
Light  Necessary,  increased  by  using  a  parallel  beam  of  light,  so 
that  we  might  telephone  from  one  place  to  an- 
other with  no  conducting  wire  between  the  transmitter  and  the 
receiver.  To  reduce  this  idea  to  practice  it  was  necessary  to  devise 
an  apparatus  to  be  operated  by  the  voice  of  a  speaker,  by  which 
variations  could  be  produced  in  a  parallel  beam  of  light,  corre- 
sponding to  variations  in  the  air  produced  by  the  voice.  I  pro- 
posed, therefore,  to  pass  light  through  two  plates  perforated  by 
many  small  orifices.  One  of  these  plates  was  to  be  fixed,  the 
other  was  to  be  attached  to  the  centre  of  a  diaphragm  actuated 
by  the  voice.  In  its  vibrations  the  diaphragm  would  cause  the 
movable  plate  to  slide  to  and  fro  over  the  surface  of  the  fixed 
plate,  by  turns  enlarging  and  contracting  the  free  orifices  for  the 
passage  of  light.  The  parallel  beam  emerging  from  this  ap- 
paratus could  be  received  at  some  distant  place  on  a  lens  focussing 


TREATMENT  OF  SELENIUM         397 

it  upon  a  sensitive  piece  of  selenium  placed  in  a  local  circuit,  with 
a  telephone  and  a  galvanic  battery.  The  variations  in  the  light 
produced  by  a  speaker's  voice  should  cause  corresponding  varia- 
tions in  the  electrical  resistance  of  the  selenium  at  the  distant 
place,  and  the  telephone  in  circuit  with  the  selenium  should 
reproduce  audibly  the  tones  and  articulations  of  the  speaker's 
voice.  It  is  greatly  due  to  the  genius  and  perseverance  of  my 
friend,  Mr.  Sumner  Tainter,  that  the  problem  thus  entered  upon 
has  been  successfully  solved. 

'The  first  point  to  which  we  devoted  our  attention  was  reducing 
the  resistance  of  crystalline  selenium  within  manageable  limits. 
The  resistance  of  selenium  cells,  employed  by 
former  experimenters,  was  counted  in  millions  %  Special 
of  ohms ;  there  is  no  record  of  a  cell  measuring 
less  than  250,000  ohms  in  the  dark.  We  have 
succeeded  in  producing  cells  measuring  only  300  ohms  in  the 
dark  and  150  in  the  light.  Our  predecessors  all  seemed  to  have 
used  platinum  for  the  conducting  part  of  their  cells,  excepting 
Werner  Siemens,  who  found  that  iron  and  copper  would  do.  We 
have  discovered  that  brass,  although  chemically  acted  upon  by 
selenium,  forms  an  excellent  material ;  indeed,  we  are  inclined  to 
believe  that  the  chemical  action  between  brass  and  selenium  has 
contributed  to  the  lowness  in  resistance  of  our  cells,  an  intimate 
union  taking  place  between  the  two  substances.  In  brass  we 
have  constructed  many  cells  of  diverse  forms.  One  of  them 
(two  are  described  by  Professor  Bell),  is  cylindrical  so  that  it 
may  be  used  with  a  concave  reflector  instead  of  with  a  lens.  It  is 
composed  of  many  metallic  disks  separated  by  mica  disks  slightly 
smaller  in  diameter.  The  spaces  between  the  brass  disks  over 
the  mica  are  filled  with  selenium,  and  the  alternate  brass  disks  are 
metallically  connected.  The  selenium  is  applied  to  the  cell  duly 
heated :  next  comes  annealing.  To  effect  this  an  oven  is  inserted 
in  a  pot  of  linseed  oil  standing  upon  glass  supports  in  another 
similar  pot  of  linseed  oil.  The  whole  is  then  heated  to  about 
214°  C,  and  kept  there  for  twenty-four  hours,  then  allowed  to 
cool  down  during  forty  to  sixty  hours  until  the  temperature  of 
ordinary  air  is  reached. 


398        ALEXANDER  GRAHAM  BELL 


"We  have  devised  more  than  fifty  forms  of  photophonic  trans- 
mitters.    In  one  of  them  (several  others  are  described  by  Pro- 
fessor Bell),  a  beam  of  light  passes  through 
A  Perfected         a  lens  of  variable  focus  formed  of  two  sheets 
Transmitter.         of  thin  glass  or  mica  containing  between  them 
a  transparent  liquid  or  gas.    When  vocal  vibra- 
tions are  communicated  to  this  gas  or  liquid,  they  cause  a  vibra- 
tory change  in  the  convexity  of  the  glass  surfaces  with  a  corre- 
sponding change  in  the  intensity  of  the  light  as  it  falls  upon  the 
selenium.    We  have  found  the  simplest  apparatus  to  consist  in  a 

plane  mirror  of  flexible  material, 
such  as  silvered  mica  or  microscope 
glass,  against  the  back  of  which  the 
speaker's  voice  is  directed. 

"A  large  number  of  trials  of  this 
apparatus  have  been  made  with  the 
transmitting  and  receiving  instru- 
ments so  far  apart  that  sounds  could 
not  be  heard  directly  through  the  air. 
In  a  recent  experiment  Mr.  Tainter 
operated  the  transmitting  instru- 
ment, placed  on  the  top  of  the 
Franklin  School  House  in  Washing- 
ton, D.  C. ;  the  receiver  being  ar- 
ranged in  a  window  of  my  labora- 
tory, at  a  distance  of  213  metres.  Upon  placing  the  telephone  to 
my  ear,  I  heard  distinctly  from  the  illuminated  receiver:  'Mr. 
Bell,  if  you  hear  what  I  say,  come  to  the  window  and  wave  your 
hat.' 

"We  have  found  that  articulate  speech  can  be  reproduced  by 
the  oxyhydrogen  light,  and  even  by  a  beam  from  a  kerosene  lamp. 
The  loudest  effects  follow  upon  interrupting  the  light  by  means 
of  a  perforated  disk  swiftly  rotated.  Because  this  apparatus  is 
noiseless  it  allows  a  close  approach  of  the  receiver  while  not 
interfering  with  its  message. 

"We  have  endeavored  to  ascertain  the  nature  of  the  rays  which 
affect  selenium,  placing  in  the  path  of  an  intermittent  beam 
various  absorbing  substances.  In  these  experiments  Professor 


Selenium  cylinder  with 
reflector. 


LIGHT  BY  ITSELF  IS  VOCAL        890 

Cross  has  rendered  us  aid.  When  a  solution  of  alum,  or  bisul- 
phide of  carbon,  is  employed,  there  is  but  slight  reduction  in 
loudness,  but  a  solution  of  iodine  in  bisulphide  of  carbon  cuts 
off  most  of  the  audible  effect.  Even  an  opaque  sheet  of  hard 
rubber  is  less  obstructive. 

"It  is  a  well  known  fact  that  the  molecular  disturbance  pro- 
duced in  a  mass  of  iron  by  the  magnetizing  influence  of  an  inter- 
mittent electrical  current  can  be  observed  as 
sound  by  placing  the  ear  in  close  contact  with        Experiments 
the  iron.     It  occurred  to  us  that  the  molecular 

1  elepnone. 

disturbance  produced  in  crystalline  selenium  by 
the  action  of  an  intermittent  beam  of  light  should  be  audible  in  a 
similar  manner  with  no  telephone  or  battery.  Many  experiments 
were  made  to  verify  this  theory;  at  first  without  definite  results. 
The  behavior  of  the  hard  rubber  just  mentioned  suggested  listen- 
ing to  it  also.  This  was  tried  with  an  extraordinary  result.  I 
held  the  sheet  in  close  contact  with  my  ear  while  a  beam  of  inter- 
mittent light  was  focussed  upon  it  through  a  lens.  A  distinct 
musical  note  was  immediately  heard.  Other  substances,  as  enu- 
merated at  the  outset  of  my  address,  were  now  successively  tried 
in  the  form  of  thin  disks,  in  every  case  with  success.  On  the 
whole,  we  feel  warranted  in  announcing  as  our  conclusion  that 
sounds  can  be  produced  by  the  action  of  a  variable  light  from  sub- 
stances of  all  kinds  in  the  form  of  thin  diaphragms.  The  reason 
why  thin  diaphragms  are  more  effective  than  masses  appears  to 


A  perforated  disc  rotated  yields  a  succession  of  sounds  from  light 

be  that  the  molecular  disturbance  produced  by  light  is  chiefly  a 
surface  action,  and  that  the  vibration  has  to  be  transmitted 
through  the  mass  of  the  substance  in  order  to  affect  the  ear.  We 


400       ALEXANDER  GRAHAM  BELL 

have  led  air,  directly  in  contact  with  an  illuminated  surface,  to 
the  ear  by  throwing  the  luminous  beam  upon  the  interior  of  a 
tube.  We  have  thus  heard  from  interrupted  sunlight  very  per- 
ceptible musical  tones  through  tubes  of  ordinary  vulcanized  rub- 
ber, of  brass,  and  of  wood.  These  were  all  the  materials  at  hand 
in  tubular  form,  and  we  have  had  no  opportunity  since  of  extend- 
ing the  observations  to  other  substances.  A  musical  tone  can  be 
heard  by  throwing  the  intermittent  beam  of  light  into  the  ear  it- 
self. This  experiment  was  at  first  unsuccessful  on  account  of  the 
position  in  which  the  ear  was  held." 


CHAPTER  XXVII 

BESSEMER,  CREATOR  OF  CHEAP  STEEL.    NOBEL,  INVENTOR 
OF  NEW  EXPLOSIVES 

Bessemer  a  man  of  golden  ignorances  .  .  .  His  boldness  and  versatility 
.  .  .  The  story  of  his  steel  process  told  by  himself  .  .  .  Nobel's  heroic 
courage  in  failure  and  adversity  .  .  .  His  triumph  at  last  .  .  .  Turns  an 
accidental  hint  to  great  profit  .  .  .  Inventors  to-day  organized  for  at- 
tacks of  new  breadth  and  audacity. 

IN  1855  Henry  Bessemer  began  to  change  the  face  of  the  civil- 
ized world  as  he  perfected  his  process  for  steel-making.  The 
story  of  his  struggles,  defeats  and  eventual  triumph  is  told  in  his 
autobiography  published  in  London  by  Engineering.1  From  that 
book  the  publishers  have  permitted  the  follow- 
ing pages  to  be  drawn.  As  a  boy  Henry  Besse-  Bessemer's 
mer  had  a  strong  mechanical  turn,  amusing  Achievements 
himself  with  a  lathe  at  an  age  when  lads  usually 
prefer  marbles  or  tag.  In  his  youth  there  was  a  clear  promise 
of  inventive  faculty,  plainly  inherited  from  his  father,  Anthony 
Bessemer,  and  naturally  pursuing  the  lines  of  paternal  interests. 
Mr.  Bessemer,  senior,  manufactured  type  of  particular  dura- 
bility ;  this  quality  his  son  discovered  due  to  additions  of  a  little 
tin  and  copper  to  the  ordinary  alloy.  It  was  in  this  field  of  alloy- 
ing that  young  Bessemer  took  his  next  step  as  an  inventor,  fore- 
shadowing the  tremendous  feat  he  was  in  due  time  to  accomplish. 
He  busied  himself  as  an  engraver  of  rollers  for  embossing  paper; 
in  cutting  their  deeply  incised  lines  there  was  a  tendency  in  curves 
to  drag  or  blur  the  surface  of  the  metal.  After  several  unsuccess- 
ful attempts  he  produced  an  alloy  of  tin  and  bismuth  free  from 
this  fault. 

Soon  afterward  Bessemer's  attention  was  directed  to  the  bronze 

1  "Sir  Henry  Bessemer :  an  Autobiography."    Offices  of  Engineering,  36 
Bedford  St.,  Strand,  London,  1905.    16  shillings. 

401 


402  SIR  HENRY  BESSEMER 

powders  sold  at  high  prices  to  printers  and  decorators.  These 
powders  were  produced  by  hand  in  Germany  by  processes  so 
laborious  as  to  make  the  cost  enormous.  Examining  the  material 
with  a  powerful  microscope  Bessemer  was  convinced  that  he 
could  dispense  with  hand  labor,  and  turn  out  a  powder  of  equal 
quality  at  nominal  expense.  His  machinery  for  this  purpose 
proved  a  success  and  laid  the  foundation  of  his  fortune;  un- 
patented  and  worked  in  secret  for  thirty-five  years,  it  yielded  him 
a  huge  profit  indispensable  for  the  costly  experiments  he  had  ever 
in  hand.  Naturally  enough  his  fame  as 'a  man  of  ingenuity  was 
promptly  noised  abroad,  and  his  talents  were  next  invoked  for 
a  much-needed  improvement  of  sugar-cane  milling.  The  moment 
that  Bessemer  saw  a  cane-mill  at  work  he  placed  his  finger  on 
the  chief  cause  of  its  wastefulness.  He  noticed  that  the  cane  was 
squeezed  between  two  rollers  for  only  a  second,  a  period  so  short 
that  the  cane  at  once  re-expanded  and  re-absorbed  much  juice. 
He  forthwith  designed  a  press,  on  much  the  same  principle  as  a 
hydraulic  press,  which  subjected  the  cane  to  severe  pressure  for 
two  and  a  half  minutes,  until  every  drop  of  juice  had  left  the 
fibres,  almost  doubling  the  output  of  the  old  machinery.  For 
success  in  this  task  Bessemer  declares  himself  indebted  to  a  golden 
ignorance.  He  says :  "I  had  an  immense  advantage  over  many 
others  dealing  with  the  problem  under  consideration,  inasmuch 
as  I  had  no  fixed  ideas  derived  from  long-established  practice 
to  control  and  bias  my  mind,  and  did  not  suffer  from  the  too- 
general  belief  that  whatever  is,  is  right.  Hence  I  could,  without 
check  or  restraint,  look  the  question  steadily  in  the  face,  weigh 
without  prejudice  or  preconceived  notions,  all  the  pros  and  cons, 
and  strike  out  fearlessly  in  an  absolutely  new  direction  if  thought 
desirable." 

But  in  his  case  ignorance  in  one  field  was  joined  to  knowledge 
in  many  another  field,  and  there  he  found  weapons  wherewith 
to  surmount  an  old  difficulty  at  a  quarter  never  assaulted  before. 
He  continues :  "The  first  bundle  of  canes  I  ever  saw  had  not 
arrived  from  Madeira  a  week  before  I  had  settled  in  my  own 
mind  certain  fundamental  principles,  which  I  believed  must  gov- 
ern all  attempts  to  get  practically  the  whole  juice  from  the  cane ; 
but,  of  course,  there  were  many  circumstances  that  rendered  it 


Copyright.  London  Stereoscopic  Co. 

THE  LATE  SIR   HENRY   BESSEMER 
OF  LONDON. 


FIRST  EXPERIMENTS  WITH  IRON   403 

necessary  to  modify  first  principles,  having  reference  to  cost  of 
construction,  lightness  for  easy  transit  across  country,  freedom 
from  necessity  for  repairs,  and  the  like." 

In  the  supreme  effort  of  his  life  Bessemer  once  more  held  him- 
self a  debtor  to  his  ignorance,  to  the  fact  that  his  mind  was  un- 
worn by  routine  and  ruttiness.  Referring  to 
his  attempt  to  make  a  cheap  metal  stronger 
than  cast  iron  for  guns,  he  says :  "My  knowl- 
edge of  iron  metallurgy  was  at  that  time  very  limited,  and  con- 
sisted only  of  such  facts  as  an  engineer  must  necessarily  observe 
in  the  foundry  or  smith's  shop ;  but  this  was  in  one  sense  an  ad- 
vantage to  me,  for  I  had  nothing  to  unlearn.  My  mind  was  open 
and  free  to  receive  any  new  impressions,  without  having  to 
struggle  against  the  bias  which  a  life-long  practice  of  routine 
cannot  fail  more  or  less  to  create." 

Now  appears  the  genius  of  the  man,  showing  that  if  his  brain 
was  unoccupied  by  rules-of -thumb  it  was  full  to  overflowing  with 
original  and  sound  ideas.  He  goes  on  to  say :  "A  little  reflec- 
tion, assisted  by  a  good  deal  of  practical  knowledge  of  copper 
and  its  alloys,  made  me  reject  all  these  from  the  first,  and  look 
to  iron  or  some  of  its  combinations,  as  the  only  material  suitable 
for  heavy  ordnance."  Of  fascinating  interest  is  the  great  in- 
ventor's story  of  how  step  by  step  he  arrived  at  his  final  success. 
After  reciting  his  preliminary  experiments,  in  an  endeavor  to 
remove  carbon  from  pig  iron  so  as  to  make  malleable  iron  and 
steel,  he  says : 

"On  my  return  from  the  Ruelle  gun-foundry  I  resumed  my 
experiments  with  the  open-hearth  furnace,  when  some  pieces  of 
pig  iron  on  one  side  of  the  bath  attracted  my  attention  by  re- 
maining unmelted  in  the  great  heat  of  the  furnace,  and  I  turned 
on  a  little  more  air  through  the  fire-bridge  with  the  intention  of 
increasing  the  combustion.  On  again  opening  the  furnace  door, 
after  an  interval  of  half  an  hour,  these  two  pieces  of  pig  still 
remained  un fused.  I  then  took  an  iron  bar,  with  the  intention 
of  pushing  them  into  the  bath,  when  I  discovered  that  they  were 
merely  shells  of  decarburized  iron,  showing  that  atmospheric  air 
alone  was  capable  of  wholly  decarburizing  grey  pig  iron,  and  con- 
verting it  into  malleable  iron  without  puddling  or  any  other 


404  SIR  HENRY  BESSEMER 

manipulation.  Thus  a  new  direction  was  given  to  my  thoughts, 
and  after  due  deliberation  I  became  convinced  that  if  air  could 
be  brought  into  contact  with  a  sufficiently  extensive  surface  of 
molten  crude  iron,  it  would  rapidly  convert  it  into  malleable  iron. 
Without  loss  of  time  I  had  some  fire-clay  crucibles  made  with 
dome-shaped  perforated  covers,  and  also  with  some  fire-clay 
blow-pipes,  which  I  joined  on  to  a  three- foot  length  of  one-inch 
gas  pipe,  the  opposite  end  of  which  was  attached  by  a  piece  of 
rubber  tubing  to  a  fixed  blast  pipe.  This  elastic  connection  per- 
mitted of  the  blow  pipe  being  easily  introduced  into  and  with- 
drawn from  the  crucible  which,  in  effect,  formed  a  converter. 
About  ten  pounds  of  molten  grey  pig  iron  half  filled  the  crucible, 
and  thirty  minutes'  blowing  was  found  to  convert  this  metal  into 
soft  malleable  iron.  Here  at  least  one  great  fact  was  demon- 
strated, namely,  the  absolute  decarburization  of  molten  crude  iron 
without  any  manipulation,  but  not  without  fuel,  for  had  not  a 
very  high  temperature  been  kept  up  in  the  air  furnace  all  the  time 
this  quiet  blowing  for  thirty  minutes  was  going  on,  it  would 
have  resulted  in  the  solidification  of  the  metal  in  the  crucible  long 
before  complete  carburization  had  been  effected.  Hence  arose  the 
all-important  question :  Can  sufficient  internal  heat  be  produced 
by  the  introduction  of  atmospheric  air  to  retain  the  fluidity  of  the 
metal  until  it  is  wholly  carburized  in  a  vessel  not  externally 
heated  ?  This  I  determined  to  try  without  delay,  and  I  fitted  up  a 
larger  blast-cylinder  in  connection  with  a  20  horse-power  engine 
which  I  had  daily  at  work.  I  also  erected  an  ordinary  founder's 
cupola,  capable  of  melting  half  a  ton  of  pig  iron.  Then  came  the 
question  of  the  best  form  and  size  for  the  experimental  con- 
verter. I  had  very  few  data  to  guide  me  in  this,  as  the  crucible 
converter  was  hidden  from  view  in  the  furnace  during  the  blow. 
I  found,  however,  that  slag  was  produced  during  the  process, 
and  escaped  through  holes  in  the  lid.  Owing  to  this,  I  constructed 
a  very  simple  form  of  cylindrical  converter,  about  four  feet  in 
interior  height,  sufficiently  tall  and  capacious,  I  believed,  to  prevent 
anything  but  a  few  sparks  and  heated  gases  from  escaping 
through  a  central  hole  made  in  the  flat  top  of  the  vessel  for  that 
purpose.  This  converter  had  six  horizontal  tuyeres  arranged 
around  the  lower  part  of  it ;  these  were  connected  by  six  adjust- 


THE  FIRST  BESSEMER  STEEL       405 

able  branch  pipes,  deriving  their  supply  of  air  from  an  annular 
rectangular  chamber,  extending  around  the  converter. 

"All  being  thus  arranged,  and  a  blast  of  10  or  15  pounds'  pres- 
sure turned  on,  about  seven  hundred-weight  of  molten  pig  iron 
was  run  into  the  hopper  provided  on  one  side  of  the  converter 
for  that  purpose.  All  went  on  quietly  for  about  ten  minutes; 
sparks  such  as  are  commonly  seen  when  tapping  a  cupola,  accom- 
panied by  hot  gases,  ascended  through  an  opening  on  the  top  of 
the  converter,  just  as  I  had  supposed  would  be  the  case.  But 
soon  after  a  rapid  change  took  place ;  in  fact,  the  silicon  had  been 
quietly  consumed,  and  the  oxygen,  next  uniting  with  the  carbon, 
sent  up  an  ever-increasing  stream  of  sparks  and  a  voluminous 
white  flame.  Then  followed  a  succession  of  mild  explosions, 
throwing  molten  slags  and  splashes  of  metal  high  up  into  the  air, 
the  apparatus  becoming  a  veritable  volcano  in  a  state  of  active 
eruption.  No  one  could  approach  the  converter  to  turn  off  the 
blast,  and  some  low,  flat,  zinc-covered  roofs,  close  at  hand,  were 
in  danger  of  being  set  on  fire  by  the  shower  of  red-hot  matter 
falling  on  them.  All  this  was  a  revelation  to  me,  as  I  had  in  no 
way  anticipated  such  violent  results.  However,  in  ten  minutes 
more  the  eruption  had  ceased,  the  flame  died  down,  and  the  pro- 
cess was  complete.  On  tapping  the  converter  into  a  shallow  pan 
or  ladle,  and  forming  the  metal  into  an  ingot,  it  was  found  to  be 
wholly  decarburized  malleable  iron.  Such  were  the  conditions 
under  which  the  first  charge  of  pig  iron  was  converted  in  a 
vessel  neither  internally  nor  externally  heated  by  fire." 

The  narrative  continues  with  details  of  further  masterly  ex- 
periments until  the  new  process  was  turning  out  steels  of  excel- 
lent quality,  containing  any  desired  fraction  of  carbon,  at  a  cost 
of  but  six  to  seven  pounds  sterling  per  ton  as  against  fifty  to 
sixty  pounds  by  the  methods  which  Bessemer  laid  upon  the  shelf. 
His  predecessors  had  made  forty  to  fifty  pounds  of  steel  at  a 
time  in  small  crucibles,  he  made  five  tons  in  twenty  minutes.  In 
his  magnificent  simplification  Bessemer  at  a  stroke  dismissed  a 
long  series  of  troublesome  processes  long  believed  to  be  as  un- 
avoidable as  winter's  cold.  He  did  away  with  the  smelting  of 
pig  iron,  the  rolling,  shearing  and  piling  of  bars,  and  the  heating 
furnace.  From  the  beginning  of  the  Bessemer  manufacture  to 


406 


SIR  HENRY  BESSEMER 


the  present  hour,  its  main  output  has  been  rails  for  railroads. 
In  this  single  service  the  debt  due  to  Bessemer  surpasses  com- 
putation, for  his  steel  has  as  least  six-fold  the  durability  of  the 


ed 


iron  it  has  replaced.  A  rail  laid  at  Crewe  Station  in  1863,  weigh- 
ing twenty  pounds  to  the  yard,  was  turned  in  1866  and  taken  up  in 
1875 ;  it  was  estimated  that'  72,000,000  tons  had  passed  over  it, 
while  the  greatest  wear  of  its  tables  was  but  .85  inch. 


GLASS-MAKING  407 

Bessemer  did  not  at  once  enter  upon  success  in  the  practical 
application  of  his  process.  British  pig  iron,  with  which  he  dealt, 
abounded  in  phosphorus,  an  element  which  he  could  not  drive  out, 
and  which  made  his  steels  faulty.  It  was  only  when,  at  length, 
he  obtained  pure  pig  iron  from  Sweden  that  he  was  able  to  sup- 
ply the  market  with  pure,  soft  malleable  iron,  and  with  steels  of 
various  degrees  of  hardness.  In  a  sequel,  full  of  interest,  he 
sketches  the  shrewd  means  by  which  he  secured  a  handsome 
fortune  from  his  great  invention,  for  Bessemer  had  remarkable 
business  ability  as  well  as  inventive  genius.  His  labors  in  steel- 
making  obliged  him  to  neglect  his  devices  in  the  plate-glass  manu- 
facture which,  despite  their  merit,  were  also  neglected  by  the 
producers  of  plate-glass.  He  remarks :  "The  simple  fact  is  that 
an  invention  must  be  nursed  and  tended  as  a  mother  nurses  her 
baby,  or  it  inevitably  perishes." 

So  far  from  finding  it  gainful  to  concentrate  his  mind  on  a 
single  problem,  ignoring  every  other,  Bessemer  delighted  in 
pursuing  a  wide  variety  of  experiments,  espe- 
cially before  his  engrossing  responsibilities  in  Bessemer's 
the  manufacture  of  steel.  In  glass-making  he  Versatility, 
introduced  some  notable  improvements.  He  tells  us :  "In  going 
over  a  glass-works  I  had  noticed  what  I,  at  the  moment,  thought 
was  a  great  oversight  in  the  mode  of  proceeding.  The  materials 
employed,  namely,  sand,  lime  and  soda  in  ascertained  quantities, 
were  laid  in  heaps  upon  the  paved  floor  of  the  glasshouse,  and 
a  laborer  proceeded  to  shovel  them  into  one  large  heap,  turning 
over  the  powdered  materials,  and  mixing  them  together;  a  cer- 
tain quantity  of  oxide  of  manganese  was  added  during  the  general 
mixing  operation,  for  the  purpose  of  neutralizing  the  green  color 
given  to  glass  by  the  small  amount  of  oxide  of  iron  contained 
in  the  sand.  The  materials  were  then  thrown  into  the  large  glass 
pots,  which  were  already  red-hot  inside  the  furnace.  What  ap- 
peared to  me  to  be  wanting  in  this  rough-and-ready  operation 
was  a  far  more  intimate  blending  of  these  dry  materials.  A  grain 
of  sand  lying  by  itself  is  infusible  at  the  highest  temperature 
attainable  in  a  glass  pot,  and  the  same  may  be  said  of  a  small 
lump  of  lime ;  but  both  are  soluble  in  alkali,  if  it  be  within  their 
reach.  These  dry  powders  do  not  make  excursions  in  a  glass  pot 


408  SIR  HENRY  BESSEMER 

and  look  about  for  each  other,  and  if  they  lie  separated  the  time 
required  for  the  whole  to  pass  into  a  state  of  solution  will  greatly 
depend  on  their  mutual  contact.  In  such  matters  I  always  reason 
by  analogy,  and  look  for  confirmation  of  my  views  to  other  manu- 
factures or  processes  with  which  I  may  happen  to  have  become 
more  or  less  acquainted.  I  may  here  remark  that  I  have  always 
adopted  a  different  reading  of  the  old  proverb,  'A  little  knowl- 
edge is  a  dangerous  thing' ;  this  may  indeed  be  true,  if  your 
knowledge  is  equally  small  on  all  subjects;  but  I  have  found  a 
little  knowledge  on  a  great  many  different  things  of  infinite  service 
to  me.  From  my  early  youth  I  had  a  strong  desire  to  know  some- 
thing of  any  and  all  the  varied  manufactures  to  which  I  have 
been  able  to  gain  access,  and  I  have  always  felt  a  sort  of  annoy- 
ance whenever  any  subject  connected  with  manufacture  was 
mooted  of  which  I  knew  absolutely  nothing.  The  result  of  this 
feeling,  acting  for  a  great  many  years  on  a  powerful  memory, 
has  been  that  I  have  really  come  to  know  this  dangerous  little 
of  a  great  many  industrial  processes.  I  have  been  led  to  say  this 
so  as  to  illustrate  my  observations  on  the  extreme  slowness  of  the 
fusion  of  glass  by  an  analogy  in  the  manufacture  of  gunpowder. 
I  have  shown  it  impossible  for  the  dry  powdered  materials  em- 
ployed in  the  manufacture  of  glass  to  react  chemically  upon  each 
other  when  they  are  lying  far  apart.  Now  if  I  take  the  three 
substances,  charcoal,  nitre  and  sulphur,  of  which  gunpowder  is 
composed,  and  break  them  into  small  fragments,  then  shake  them 
loosely  together,  and  put  a  pound  or  two  of  this  mixture  on  a 
stone  floor  and  apply  a  match,  the  nitre  will  fizzle  briskly,  the 
sulphur  will  burn  fitfully  or  go  out,  and  the  charcoal  will  last 
several  minutes  before  it  is  consumed.  If,  instead  of  this  crude 
and  imperfect  mixture,  we  take  the  trouble  to  grind  these  ingre- 
dients under  edge-stones  into  a  fine  paste  with  water,  and  then 
dry  and  granulate  it,  we  have  still  the  precise  chemical  elements  to 
deal  with  which  we  ignited  on  the  stone  floor ;  but  they  now  exist  in 
such  close  and  intimate  contact  as  instantly  to  act  upon  each  other, 
and  a  ton  or  two  of  these  otherwise  slow-burning  materials  will 
be  converted  into  gas  in  the  fraction  of  a  second.  The  inference 
was  simple  enough,  namely,  to  grind  together  the  materials  re- 


DRIES  OILS  409 

quired  to  form  glass,  and  when  the  heat  of  the  furnace  arrives 
at  the  point  where  decomposition  takes  place,  the  whole  will  pass 
into  the  fluid  state  much  more  quickly,  and  will  yield  a  much  more 
homogeneous  glass  than  is  obtained  in  the  usual  manner." 

Bessemer  one  day  paid  a  visit  to  the  works  of  his   friends, 
Hayward  and  Company,  London,  manufacturers  of  paints  and 
varnishes.     He  was  struck  with  the  wasteful- 
ness   and    imperfection    of    the    time-honored        Improves  the 
e     ,  ...  .  Drying  of  Oils. 

process  of  drying  oils  in  an  iron  pot  over  an 

open  fire;  a  crude  method  always  attended  with  danger,  and  not 
seldom  with  a  complete  loss  of  the  heated  oil.  As  he  walked 
through  the  works  there  occurred  to  him  a  much  better  plan 
which  he  at  once  embodied  in  a  sketch.  His  ideas  were  put  into 
practice  by  his  friends,  to  their  lasting  profit.  Instead  of  a  small 
charge  of  two  or  three  gallons  heated  over  an  open  fire,  he  sug- 
gested that  fifty  or  sixty  gallons  should  be  run  into  a  tank,  in 
the  bottom  of  which  was  a  pipe  terminating  in  a  large  rose-head. 
Connected  with  this  pipe  was  a  coil  that  could  be  heated  to  any 
desired  temperature,  and  air  could  be  forced  through  this  coil, 
escaping  through  the  rose-head  into  the  oil.  The  exact  degree  of 
heat  required  could  be  thus  maintained,  and  the  process  com- 
pleted with  certainty  and  safety,  without  waste,  and,  above  all, 
with  no  discoloration  of  the  oil.  This  method,  carried  to  a 
further  degree  of  oxidation,  is  the  foundation  of  the  vast  lino- 
leum industry  throughout  the  world. 

It  was  in  trying  to  make  guns  of  a  new  strength  that  Sir  Henry 
Bessemer  entered  the  path  which  enabled  him  to  make  steel  at 
little  more  cost  than  cast  iron.     It  was  in  pro- 
viding guns  with  explosives  of  new  power  that        Alfred  Nobel 

Alfred  Nobel  won  both  distinction  and  fortune. 

Isxplosives. 

As  in  the  case  of  Sir  Henry  Bessemer,  his  gifts 
have  inured  vastly  more  to  the  service  of  peace  than  of  war. 
It  is  estimated  that  during  the  Civil  War,  1861-65,  more  explo- 
sives were  used  in  the  United  States  by  civil,  railroad,  mining 
and  quarrying  engineers  than  in  the  field  of  battle.  Chief  of 
these  explosives  was  gunpowder ;  nitro-glycerine,  though  well 
known,  had  then  little  or  no  acceptance,  for  good  reasons.  How 


410  ALFRED  NOBEL 

its  defects  were  overcome  is  told  by  Mr.  Henry  de  Mosenthal 
in  an  article  on  Alfred  Nobel,  in  the  Nineteenth  Century  Maga- 
zine, London,  October,  1898.  By  the  editor's  kind  permission 
that  article  is  here  freely  drawn  upon. 

Nitro-glycerine,  discovered  by  Sobrero  in  1847,  i§  made  by 
treating  glycerine  with  a  mixture  of  nitric  and  sulphuric  acids ; 
it  is  poisonous,  very  sensitive  to  a  shock,  and  most  dangerous  to 
handle.  Being  liquid  it  runs  into  the  fissures  of  rock  when 
poured  into  a  bore-hole,  and  requires  to  be  carefully  confined 
that  it  may  explode  when  ignited  by  means  of  a  simple  fuse. 
Nobel  tried  to  overcome  these  deficiencies,  first  by  mixing  the 
liquid  with  gunpowder,  and  then  by  adding  fluids  which  ren- 
dered it  non-explosive,  so  that  it  could  be  safely  transported,  the 
added  liquid  being  removed  just  before  use ;  he  also  suggested 
confining  it  in  a  tube  having  the  shape  of  a  bore-hole,  and  firing 
it  by  means  of  a  small  gunpowder  cartridge  or  primer.  But  all 
this  did  not  avail,  and  accidents  occurred  so  frequently  that  the 
use  of  the  blasting  oil  was  prohibited  in  Belgium,  in  Sweden, 
and  later  on  in  England.  A  vessel  carrying  some  cases  shipped 
from  Hamburg  and  bound  for  Chili  was  blown  up,  and  the  event 
caused  such  a  sensation  that  it  seemed  as  if  the  use  of  nitro- 
glycerine would  be  prohibited  the  world  over.  In  the  meantime, 
however,  Nobel  had  solved  the  problem  of  its  safe  use,  and  at  the 
end  of  1866  he  had  invented  a  compound,  which  he  called  dyna- 
mite, made  by  mixing  the  nitro-glycerine  oil  with  porous  absorb- 
ing material,  thus  converting  it  into  a  paste.  Dynamite  proved 
on  experiment  to  be  comparatively  insensitive  to  a  shock  or  a 
blow;  it  burnt  when  ignited,  and  could  be  properly  exploded 
only  by  means  of  a  powerful  detonator  fixed  to  the  end  of  the 
fuse  and  inserted  into  the  plastic  explosive. 

The  invention  of  dynamite  marks  an  epoch  in  the  history  of 
civilization.  In  judging  of  the  degrees  of  culture  of  a  people, 
we  are  guided  to  a  great  extent  by  the  kind  of  roads  and  water- 
ways they  have  constructed,  and  by  the  facility  with  which  they 
have  obtained  metals  and  applied  them  to  the  arts.  The  Romans 
constructed  excellent  roads  on  the  level,  but  in  the  mountains 
they  could  only  make  narrow  and  very  steep  paths.  Canals  and 


COLLODION  GIVES  A  HINT          411 

cuttings  were  made  with  great  sacrifice  and  labor,  and  only  where 
the  soil  was  soft.  Thus  Suetonius  states  that  in  order  to  make 
a  cutting  about  three  miles  long  to  drain  the  Lacus  Fucinus,  the 
Emperor  Claudius  employed  30,000  men  for  eleven  years.  In 
the  sixteenth  century  road  making  and  mining  were  scarcely  more 
advanced.  It  took  150  years,  ending  with  1685,  to  mine  five  miles 
of  gallery  in  the  Hartz  mountains.  Although  blasting  with 
gunpowder  dates  back  to  the  seventeenth  century,  it  did  not  come 
into  general  use  until  about  the  middle  of  the  eighteenth  century, 
at  which  time  the  total  cubage  mined  in  Great  Britain  amounted 
to  little  more  than  of  a  large  railway  cutting  at  the  present  day. 
The  use  of  gunpowder  gave  a  great  impetus  to  mining  and  public 
works,  but  it  was  only  the  introduction  of  railways,  and  the  neces- 
sity of  laying  the  lines  on  easy  gradients,  which  raised  blasting 
to  a  science.  The  introduction  of  dynamite,  thrice  as  powerful  as 
gunpowder  and  much  more  reliable,  entirely  revolutionized  that 
science,  and  made  it  possible  to  execute  the  gigantic  engineering 
works  of  our  time,  and  brought  about  that  prodigious  develop- 
ment of  the  mining  industry  of  the  world  which  we  have  wit- 
nessed since  1870. 

Dynamite  is  combined  with  twenty-five  per  cent,  of  inert  mat- 
ter as  an  absorbent;  for  this  large  proportion  of  unexploding 
substance,   Nobel  sought  an  active  substitute. 
This,  he  thought,  might  be  a  substance  which      Nobel  Profits  by 
would  dissolve  in  nitro-glycerine  so  as  to  form         an  Accident, 
a  homogenous  paste.    Now  for  a  sagacious  ex- 
periment with  a  liquid  brought  to  his  hand  by  accident.     Whilst 
experimenting  in  search  of  such  a  material,  he  one  day  cut  his 
finger  and  sent  out  for  some  collodion  to  form  an  artificial  skin 
to  protect  the  wound ;  having  used  a  few  drops  for  that  purpose, 
it  occurred  to  him  to  pour  the  remainder  into  some  nitro-glycer- 
ine, and  he  thus  discovered  blasting  glycerine,  which  he  patented 
in  December,  1875.    Collodion  is  made  by  dissolving  a  gun-cotton 
in  a  volatile  solvent,  a  mixture  of  ether  and  alcohol,  and  Nobel 
suggested  that  the  viscous   substance  thus  obtained   should  be 
mixed  with  the  nitro-glycerine  so  as  to  form  a  jelly.    On  further 
experiment  the  jelly  was  dispensed  with,  and  blasting  gelatine 


412  ALFRED  NOBEL 

was  made,  as  it  is  now,  by  warming  the  nitro-glycerine,  and 
adding  about  eight  per  cent,  of  a  gun-cotton  which  was  found 
to  be  soluble  in  nitro-glycerine.  The  new  explosive,  half  as 
strong  again  as  dynamite,  was  too  violent  to  be  applicable  to  any 
but  the  hardest  rock.  Nobel,  however,  discovered  how  to  mod- 
erate its  action,  and  gelatine  dynamite  and  gelignite  were  manu- 
factured by  the  addition  of  saltpetre  and  wood-meal  to  a  blasting 
gelatine  of  less  consistency  than  that  employed  without  such  ad- 
mixture. Blasting  gelatine  was  used  in  large  quantities  in  the 
piercing  of  the  St.  Gothard  tunnel,  where  the  rock  was  so  hard 
that  no  satisfactory  work  could  be  done  without  it.  Since  then 
the  use  of  the  gelatine  explosives  has  increased  more  and  more, 
and  in  some  countries  they  have  entirely  superseded  dynamite. 

The  smokeless  powder  which  Nobel  originated  was  based  on 
his  discovery  that  by  means  of  heated  rollers  he  could  incor- 
porate with  nitro-glycerine  a  very  high  per- 
Nobel  Invents       Centage  of  that  soluble  nitro-cellulose,  or  gun 
Powder  cotton,  which  his  factories  were  using  in  the 

manufacture  of  blasting  gelatine.  Blasting 
gelatine  altered  by  means  of  moderating  substances,  had  been 
tried  in  guns  and  had  burst  them.  Nobel  now  found  that  if  the 
nitrated  cotton  was  increased  from  eight  to  about  fifty  per  cent, 
he  obtained  a  powder  suitable  for  firearms.  The  progress  in  the 
construction  of  weapons,  and  especially  the  introduction  of  quick- 
firing  guns,  made  it  necessary  to  have  smokeless  powder,  while 
higher  velocities  demanding  straighter  paths  for  projectiles  could 
be  attained  with  new  arms  resisting  high  pressure.  Whilst  in 
quest  of  such  a  powder,  Nobel  perfected  several  methods  for 
regulating  the  pressure  in  guns,  and  modifying  the  recoil.  It 
was  in  the  beginning  of  1888  that  he  invented  his  well-known 
smokeless  powder,  or  ballistite.  His  discovery  that  the  two  most 
powerful  shattering  explosives,  nitro-glycerine  and  gun-cotton, 
when  mixed  in  about  equal  proportions,  would  form  a  slow  burn- 
ing powder,  a  propulsive  agent  with  pressures  which  would  exceed 
the  resistance  of  modern  weapons,  caused  astonishment  in  tech- 
nical circles.  Nobel  submitted  his  powder  to  the  British  Ex- 
plosive Committee,  which  found  that  instead  of  employing  the 


COURAGE  AND  TENACITY  413 

variety  of  gun-cotton  which  is  soluble  in  nitro-glycerine  with  the 
aid  of  heat,  the  insoluble  kind  could  be  used  provided  an  assistant 
solvent  could  be  added ;  and  that  the  manufacture  could  be  carried 
on  at  lower  temperatures  than  those  necessary  in  producing  other 
explosives.  The  powder  thus  obtained  was  cordite,  and  this  they 
recommended  for  adoption. 

Physically  weak,   of   nervous,   high   strung  and  exceptionally 
sensitive  disposition,  Nobel  was  endowed  with  a  strong  will,  un- 
bounded energy,  and  wonderful  perseverance ;   (   ^obel  Bodil 
he  feared  no  danger  and  never  yielded  to  ad-   weak,  was  Strong 
versity.     Many  would  have  succumbed  under        in  Mind  and 
the  misfortunes  which  befell  him,  but  the  sue-  WilL 

cession  of  almost  insurmountable  difficulties,  the  explosion  of  his 
factory,  causing  a  general  scare  and  dread  of  the  deadly  compound 
he  was  making,  the  loss  of  his  younger  brother,  to  whom  he  was 
devotedly  attached,  the  consequent  paralysis  of  his  father,  and  his 
mother's  grief  and  anxiety,  could  not  deter  him  from  pursuing  his 
aim.  His  temerity  frequently  verged  on  foolhardiness,  as  when 
he  was  going  to  his  father's  works  one  day  at  St.  Petersburg,  and 
rinding -no  boat  to  take  him  across  the  river,  he  swam  to  the  op- 
posite bank  of  the  Neva.  The  co-existence  of  impulsive  daring 
with  sensitive  timidity  was  a  striking  feature  in  his  character.  He 
frequently  demonstrated  the  value  and  safety  of  his  explosives  with 
his  own  hands,  although  he  was  particularly  susceptible  to  head- 
aches caused  by  bringing  nitro-glycerine  in  contact  with  the  skin ; 
these  headaches  affected  him  so  violently  that  he  was  often  obliged 
to  lie  down  on  the  ground  in  the  mine  or  quarry  in  which  he  was 
experimenting.  On  one  occasion  when  some  dynamite  could  not 
be  removed  from  a  large  cask  he  crept  into  it  and  dug  the  ex- 
plosive out  with  a  knife.  Many  other  incidents  could -be  related 
of  the  fearlessness  he  displayed  when  the  success  of  his  invention 
depended  entirely  upon  his  demonstrations  of  its  safety,  which  in 
those  days  had  not  yet  been  thoroughly  proved. 

Nobel  died  in  1896,  at  the  age  of  63 ;  after  providing  legacies  to 
relatives  and  friends  he  left  about  $12,000,000,  its  income  to  be 
annually  divided  into  fifths,  each  fifth  to  be  awarded  for  the  most 
important  discovery  or  improvement  in  chemistry,  physics,  physiol- 


414          CO-OPERATIVE  INVENTION 

ogy,  or  medicine,  and  for  the  work  in  literature  highest  in  the 
ideal  sense.  In  distributing  these  prizes  no  considerations  of 
nationality  prevail. 

In  these  days  of  organization,  the  career  of  the  inventor  takes 
m  a  new  breadth.    If  his  ideas  are  sound,  poverty  need  be  no  bar 
to  his  success.    To-day  a  man  of  proved  ability 
nvention  WJIQ  enter^ams  an  idea  for  a  new  machine,  en- 

Organized.  . 

gine,  or  process  may  choose  among  the  great 

firms  or  companies  interested  in  the  field  he  would  enter.  His 
plans  are  then-canvassed  by  competent  critics;  if  his  suggestions 
harbor  a  fallacy  it  is  pointed  out;  if  his  aims,  though  feasible, 
would  be  unprofitable,  they  are  left  severely  alone.  Perhaps  in 
essence  his  schemes  are  good,, but  need  modification;  this  is  duly 
supplied.  Instead  of  working  all  alone  in  twilight  or  darkness, 
the  inventor  now  takes  up  experiment  with  the  aid  of  carefully 
chosen  assistants,  with  amassed  information  as  to  what  others  have 
done  in  the  same  path,  both  at  home  and  abroad. 

When  an  inventor  is  an  Edison :  as  remarkable  in.  executive 
ability  as  in  creative  power,  it  is  he  who  organizes,  as  a  general, 
the  forces  which  test  his  ideas  and  perfect  such  of  them  as  prove 
sound.  Let  Edison-  imagine  a  new  storage  battery ;  forthwith  he 
enlists  a  corps  of  chemists  and  metallurgists,  engineers  and  me- 
chanics, and  keeps  them  busy  attacking  the  difficulties  of  his  quest 
mechanical,  chemical,  electrical.  What  if  his  mathematics  go  no 
further  than  arithmetic,  are  not  masters  of  the  calculus  to  be  en- 
gaged on  moderate  terms  in  every  university  town  ?  His  personal 
command  of  the  pencil  falls*  far  short  of  the  facility  of  profes- 
sional draftsmen  who,  at  reasonable  salaries,  will  turn  out  plans 
and  elevations  quickly  and  accurately.  His  staff,  bound  to  him 
by  affection  and  pride  as  with  hooks  of  steel,  are  the  fingers  of  his 
hands  to  win  triumphs  which  neither  he  alone,  nor  his  men  by 
themselves,  could  ever  accomplish. 

It  has  been  solely  by  organized  ability,  unfaltering  faith  in 
ultimate  success,  and  massed  capital,  that  the  steam  turbine  has 
become  the  rival  of  the  steam  engine  of  Watt.  A  vast  sum,  ex- 
pended during  nine  years,  was  required  to  perfect  its  delicate  and 
exacting  mechanism.  One  day  a  young  engineer  saw  it  whirling 
away  at  high  speed ;  with  the  efficiency  of  the  gas  engine  in  mind, 


A  GREAT  ELECTRIC  LOCOMOTIVE  415 

he  asked,  "Why  not  drive  a  turbine  by  gas  instead  of  by  steam?" 
He  took  his  idea  to  a  leading  manufacturing  concern ;  it  was  ap- 
proved, and  now  that  young  inventor  is  attacking  the  diffi- 
culties, neither  few  nor  small,  which  stand  in  the  way  of  building 
an  effective  gas  turbine. 

In  these  latter  days  new  doors  are  opened  to  ingenuity  by  the 
comptehensiveness  of  great  industries,  by  the  huge  scale  on  which 
they  conduct  their  business.    A  country  black-     Great  combina- 
smith  is  served  well  enough  by  a  hand-blown  bel-         tions  create 
lows ;  at  the  Homestead  Steel  Works  the  blow-         New  Oppor- 
ing  machinery  has  been  designed  by  the  best  tumties. 

engineering  talent  in  America.  When  the  output  of  a  trust,  or 
even  of  a  single  company,  rises  to  scores  of  millions  of  dollars 
every  year,  it  is  worth  while  to  measure  how  far  moisture  in  a 
blast  may  do  harm,  and  adopt  the  elaborate  plans  of  Mr.  James 
Gayley  for  drying  air  before  sending  it  into  a  furnace.  Take  an 
example  of  how  the  United  States  Steel  Company  has  planned 
every  detail  betwixt  mine  and  mill.  Each  lake  carrier,  of  im- 
mense size,  has  its  hold  so  curved  that  automatic  clam-shells  lift 
ten  tons  of  ore  at  each  descent,  shovcler  and  shovel  being  dis- 
missed. Vessels  and  docks  dovetail  into  one  another.  The  car- 
lengths,  as  a  freight  train  stands  on  its  track,  correspond  to  the 
distance  between  one  steamer-hoist  and  the  next.  In  like  fashion 
every  link  in  the  chain  is  devised  to  save  every  possible  foot- 
pound of  energy,  every  dispensable  moment  of  time.  Capital,  al- 
ways cheaper  than  labor,  is  expended  with  both  hands",  and  in  no 
direction  more  liberally  than  in  setting  at  work  the  inventor  of 
economical  devices,  and  his  twin  brother,  the  organizer,  who  deals 
with  the  whole  industry  as  a  single  mechanism  to  be  reduced  to 
the  lowest  working  cost  and  the  highest  ultimate  efficiency. 

During  1904  the  General     Electric  Company  at  Schenectady, 
New  York,  perfected  for  the  New  York  Central  &  Hudson  River 
Railroad  an  electric  locomotive  such  as  will  be 
used  for  passenger  service  between  New  York      Team- Work  in 

and   Croton.     That   locomotive,   far  outvying       Research  and 

.,  .          ,        ,  P  Invention, 

anything  else  that  ever  before  moved  on  wheels, 

was  created  by  a  council  of  locomotive  builders,  electricians,  en- 
gineers, and  mechanics.  Some  of  the  plans  which  they  adopted 


416  ORGANIZED  ATTACKS 

with  success  had  failed  in  times  past.  Each  motor  was  made  part 
and  parcel  of  the  axle  it  turns,  a  directness  of  construction  which 
had  never  before  proved  to  be  feasible.  Usually  an  electric 
motor  has  many  magnetic  poles;  the  motors  in  this  locomotive 
have  each  only  two  poles. 

On  much  the  same  lines  this  Company  is  constantly  experiment- 
ing with  a  view  to  cheapen  and  improve  electric  lighting.  Every 
filament,  every  luminous  rod  or  vapor,  as  newly  devised,  is  tested 
and  modified  by  as  acute  a  band  of  investigators  as  exist  in  the 
world,  with  all  the  benefit  of  daily  conference  and  mutual  aid. 

In  such  fields  as  those  of  the  cheapening  of  light  and  motive 
power,  the  utilization  of  electricity,  the  production  of  metals,  it 
would  seem  that  the   day  of  the  solitary  re- 
Group  Attack.        searcher  or  inventor  is  drawing  to  a  close.    To- 
day the  man  of  original  ideas,  of  combining  fa- 
culty, of  uncommon  deftness,  of  rare  visual  accuracy,  is  mated 
with  his  peers  for  a  group  attack  on  a  many-sided  problem  where 
each  man's  resources  will  find  their  special  play.   In  untiring  labor 
at  the  bench  and  lathe,  at  the  muffle  and  the  test  tube,  one  experi- 
ment follows  another,  all  duly  compared,  judiciously  varied  and 
advanced  as  indication  may  suggest.    Thus  the  fences  which  ex- 
treme specialization  have  set  up  are  surmounted,  each  worker 
supplements  the  deficiencies  of  his  fellows,  and  all  join  hands  to 
take  by  assault  a  citadel  that  might  forever  defy  single  attack. 


CHAPTER  XXVIII 

/ 

COMPRESSED  AIR 

An  aid  to  the  miner,  quarryman  and  sculptor  .  .  .An  actuator  for  pumps 
.  .  .  Engraves  glass  and  cleans  castings  .  .  .  Dust  and  dirt  removed  by 
air  exhaustion  .  .  .  Westinghouse  air-brakes  and  signals. 

SOME  recent  noteworthy  advances  of  invention  have  been 
due  to  co-operation  by  many  workers,  not  however  on  such 
lines  of  definite  group  attack  as  have  just  been  remarked.  Among 
these  advances  may  be  chosen  for  rapid  survey  the  applications  of 
compressed  air,  of  plain  and  reinforced  concrete,  the  economy 
of  power-production  and  of  fuel  for  whatever  purpose  employed. 
Let  us  begin  with  compressed  air. 

Hammers,   drills,   and  picks,  all   working  by  percussion,  are 
among  the  most  effective  tools.    They  may  be  attached  to  a  steam 
piston,  as  are  Nasmyth  hammers  and  common 
quarry  drills,  yielding  a  much  cheaper  product     Compressed  Air. 
than  does  hand  labor.     In  many  places  where       In  Effect  Cold 

it  is  not  feasible  to  use  steam  in  this  direct  and    Steam  for  Driving 
.     .  Hammers,  Drills, 

most  economical  way,  it  is  best  to  employ  com-          and  pici£8. 

pressed  air  which  works  much  as  steam  does, 
so  that  a  motor  or  a  drill  with  no  change  of  build  may  be  operated 
by  one  or  other  motive  power  at  will.  Compressed  air,  unlike 
steam,  may  be  taken  long  distances  without  condensation ;  in  tight 
receivers  it  may  be  kept  without  any  loss  as  long  as  we  like,  and 
used  in  mines  and  tunnels  where  steam  heat  would  be  a  nuisance, 
or  where  electricity  would  be  unsafe.  Electrical  drills  and  cutters, 
moreover,  are  liable  to  have  their  insulation  harmed  by  working 
shocks,  and  by  surrounding  grit,  sand  or  chips.  In  mines  after  a 
blast  of  gunpowder,  a  direct  current  from  the  main  pipe  quickly 
freshens  the  air;  at  all  times  the  cool,  pure  breeze  from  the  ex- 
haust pipe  is  a  welcome  aid  to  ventilation.  Steam,  one  of  the 

417 


418 


COMPRESSED  AIR 


chief  servants  of  industry,  must  be  kept  and  used  hot.  When  its 
energy  is  used  to  compress  air  we  have  at  command  a  substance 
with  all  the  working  quality  of  steam,  without  having  to  keep  it 
warm.  As  it  toils  at  common  temperatures,  we  can  imagine  com- 
pressed air  to  be,  in  effect,  cold  steam. 

Of  late  years  cutters  driven  by  compressed  air  have  been  largely 
adopted  throughout  the  coal  mines  of  the  United  States.    A  cutter 


New  Ingersoll  Coal  Cutter. 
F,  trunnion.     B,  C,  piston  rings.     A,  piston.     E,  wheel. 

weighing  ten  pounds,  with  air  at  seventy-five  pounds  behind  it, 
strikes  a  blow  160  to  250  times  a  minute,  beginning  at  the  floor 


n  • 


Drill  steels. 

and  making  as  little  slack  as  a  hand  pick  intelligently  wielded. 
Other  tools,  in  great  diversity,  actuated  in  the  same  way,  ask  only 
skill  in  guidance  instead  of  muscular  drudgery.  Air  drills  are 
used  in  mines,  wells,  tunnels,  and  rock  foundations ;  at  will  the 
mechanism  impels  a  hammer  instead  of  a  drill.  Air  riveters  build 
ships  and  bridges,  as  well  as  fasten  together  the  comparatively 
small  plates  of  boilers  and  fire-boxes.  With  a  little  variation  in 
its  form  we  have  a  tool  which  caulks  boilers,  tanks,  and  ships. 
Air-hammers  light  and  strong  have  revolutionized  the  art  of  cut- 
ting and  carving  stone,  the  force  of  a  stroke  being  regulated  by  a 


SCULPTOR  AT  WORK  WITH  PNEUMATIC  CHISEL, 
HUGHES  GRANITE  AND  MARBLE  Co.,  CLYDE,  OHIO. 


OF  THE 

UNIVERSITY 

OF 


A  DEBT  TO  DENTISTRY  419 

touch.  Pneumatic  hammers  are  of  two  kinds :  Valveless  hammers 
in  which  the  piston  is  the  hammer,  opening  and  shutting  the  inlet 
and  exhaust  parts;  and  valve  hammers,  in  which  there  is  a  dis- 
tinct moving  valve.  Hammers  without  valves  are  always  short  of 


Haeseler  air-hammer. 
Ingersoll-Rand  Co.,  New  York. 


stroke,  and  are  chiefly  used  in  caulking  and  chipping.  Some  of 
them  yield  as  many  as  250  strokes  per  minute.  Valve  hammers 
do  not  move  at  this  high  pace,  rarely  exceeding  thirty-five  strokes 
per  minute,  but  each  stroke  is  comparatively  long  and  forcible 
for  riveting  and  the  like  severe  work.  In  the  Keller  hammer  the 
valve  moves  longitudinally  with  the  hammer  barrel  and  in  the 
same  direction  with  the  hammer  piston,  instead  of  in  the  opposite 
direction  as  is  usually  the  case.  A  blow,  therefore,  tends  to  seat 
the  valve  all  the  more  firmly,  instead  of  jarring  it  off  its  seat.  An- 
other result  is  that  the  tool  works  efficiently  even  when  the  valve 
is  loosened  by  much  use.  This  hammer  is  manufactured  by  the 
Philadelphia  Pneumatic  Tool  Co.,  Philadelphia. 

It  is  interesting  to  learn  from  Mr.  W.  L.  Saunders,  of  New 
York,  how  the  air-tools  just  considered  were  introduced.  He 
says  :— 

"Mr.  McCoy  is  entitled  to  the  credit  of  first  applying  pneumatic 
tools  to  heavy  work,  such  as  chipping  metals,  caulking  boilers, 
cutting  stone  and  so  on.  He  was  not,  however,  the  originator  of 
the  broad  idea,  as  long  before  he  perfected  the  tool  for  heavy 
work  it  had  been  used  as  a  dental  plugger,  a  device  working  com- 


420 


COMPRESSED  AIR 


pressed  air  in  a  cylinder  so  that  a  piston  struck  the  end  of  a  tamp- 
ing tool,  used  to  insert  gold  into  the  cavities  of  teeth." 


Rock  drill  used  as  blacksmith's  hammer. 
Ingersoll-Rand  Co.,  New  York. 

A  rock  drill,  on  occasion,  may  serve  as  a  blacksmith's  hammer. 
The  drill,  detached  from  its  tripod,  is  fastened  to  a  vertical  sup- 
port. The  ram,  duly  supplied  with  compressed  air,  is  fixed  in 

position  over  the  anvil,  upon 
which  it  descends  more  fre- 
quently if  less  forcibly  than 
a  steam  hammer.  A  rock 
drill  may  also  serve  to  drive 
drift  bolts  into  the  timbers 
of  caissons.  This  task  when 
effected  by  ordinary  sledge 
hammers  is  slow  and  costly, 
while  with  compressed  air 
as  a  servant  capital  work  is 
done  at  much  lower  expense. 
The  drill  is  provided  with 
handles  so  as  to  be  readily 
managed  by  two  men,  who 
place  the  anvil,  with  its 
cupped  end,  on  the  head  of 
the  bolt  to  be  driven.  Pneu- 
maac  energy  does  the  rest. 

With  dimensions  much  en- 
larged an  air-driven  piston  becomes  a  rammer  for  foundry  sand, 
for  roads  and  pavements,  for  tamping  the  beds  of  railroads.  In 
foundries  a  moulder  is  furnished  with  a  small  sand-sifter, 


Little  Giant  wood-boring  machine. 
Chicago  Pneumatic  Tool  Co. 


PUMPS  OF  A  NEW  KIND 


421 


vibrated  by  compressed  air;  he  is  now  free  to  use  his  shovel  all 

the  time,  so  that  he  does  five  times  as  much  work  as  before. 

Hoists  small  and  large  are  actuated  by  the  same  agency ;  in  every 

case    the    mechanism    is    so    simple    that 

rough    usage    is    withstood    and    repairs, 

when  needed,   are  easily   effected.     If  a 

ratchet,  a  pawl,  a  bearing,  wears  out,  a 

new  one  can  be  bought  at  small  cost  and 

at  once  fitted  into  place.     Designers  have 

produced  rotary  as  well  as  reciprocating 

air    tools;    of    these    a    wood-borer    is    a 

capital  example. 

Sometimes  it  is  well  worth  while  to  em- 
ploy compressed  air  simply  as  a  blast  to 
keep  a  milling-cutter  free  from  its  chips ; 
when  the  blast  is  cold,  as  it  usually  is,  the 
cutter  may  turn  all  the  quicker. 

Compressed  air  can  do  much  else  than 
impel  pistons  of  familiar  type.  In  one  re- 
markable device  it  has  put  pistons  out  of 
business  altogether. 

Fill  a  tumbler  to  the  brim  with  water, 
take  a  straw  and  dip  it  to  the  bottom  of 
the  glass,  blowing  as  heartily  as  you  can. 
At  once  the  water  overflows  because  dis- 
placed by  rising  bubbles  of  air.    Instead  of  a  tumbler  take  a  long 
upright  pipe  filled  with  water,  send  to  its  base  compressed  air  of 
adequate  pressure,  and  you  have  the  Pohle  air- 
lift, which  carries  water  into  the  reservoirs  of  Air-Lifts. 
Fort  Madison,  Iowa,  of  Dixon,  Illinois,  of  As- 
bury  Park,  New  Jersey,  and  many  other  towns  and  villages.    On 
a  smaller  scale  the  air-lift  brings  up  water  from  thousands  of 
wells,  rivers,  and  lakes.    Aboard  ship  it  moves  water  ballast  from 
one  compartment  to  another,  so  as  to  give  the  vessel  just  the 
trim  or  inclination  desired.     In  chemical  works  it  raises  liquids 
so  corrosive  that  no  other  lifter  is  feasible.    It  has  no  valves  or 
other  moving  parts  to  be  deranged  or  hurt  in  case  its  stream  bears 
sand  or  dirt,  so  that  it  is  a  capital  drainage  pump ;  after  serving 


Water  lifted  by 
compressed  air. 


422 


COMPRESSED  AIR 


thus  it  may  bring  sewage  to  farms  and  distribute  it  thoroughly. 

To  be  fairly  efficient  the  air-lift  requires  that  two  thirds  of  the 

length  of  its  upright  pipe  be  immersed  below  the  surface  of  the 

liquid  to  be  raised. 

For  oil  wells,  which  may  be  2000  or  more  feet  in  depth,  a 

lifter  not  so  simple  is  employed.    A  pipe,  comparatively  large,  is 
lowered  to  the  oil.     Its  base  forms  a  receiver 
Liquids  Lifted       which,  at  will,  may  be  closed  on  its  earthward 
by  Expanding       gide^   then  ^rough   a   small   inner   tube   com- 
pressed air  reaches  the  oil  to  force  it  bodily  to 

the  surface  of  the  ground.    The  Harris  pump  lifts  oil,  water,  or 

other  liquids  with  high  efficiency :  it  allows  the  compressed  air 

after  use  to  act  expansively ; 
this  helps  to  drive  the  com- 
pressor; then  this  expanded 
air  is  once  more  highly  com- 
pressed, and  so  recurrently. 
Compressed  air  readily 
moves  liquids  as  masses;  it 
as  easily  impels  them  as  par- 
ticles. A  lady's  toilet  table 
usually  displays  an  atomizer. 
Its  rubber  bulb,  sharply 
squeezed,  emits  a  tiny 
stream  of  perfume  as  a 
quick  air  blast  breaks  a 
drop  of  liquid  into  spray. 
Magnify  this  apparatus  and 
you  have  a  painting  machine 
for  freight  and  passenger 
cars,  fences,  and  out-build- 


ings. Driven  as  it  is  with 
projectile  force  the  pigment 
penetrates  further  than  if 
laid  on  by  hand,  reaching 
crannies  and  crevices  which  evade  a  brush.  On  the  same  prin- 
ciple Hook's  spraying  machine  sends  Bordeaux  mixture  into  the 


Harris  system  of  pumping  by  com- 
pressed air,  showing  switch.  Pneu- 
matic Engineering  Co.,  New  York. 


CLEANSING  423 

foliage  of  an  orchard,  or  delivers  a  solution  of  carbolic  acid  upon 
the    floors,    walls,   and   ceilings    of    a   hospital   or    a    sick-room. 
Strengthen  such  a  blast  and  you  can  elevate, 
dry,  and  aerate  grain,  or  lift  the  culm  from  a       A  Jack-°f~A11- 
coal  heap  to  a  furnace,  and  then  discharge  the 
ashes  as  they  tumble  from  a  grate.     Where  stretches  of  water 
are  sandy  and  muddy,  compressed  air  dredges  a  channel  by  stir- 
ring up  deposits  at  the  bottom. 

An  air  compressor  reversed  in  direction  is  an  air  exhauster, 
such   as   we   find   carrying   money   in   department   stores.      The 
powerful    in-draft    of    this    apparatus,    often 
Removing  Dust      drawing  large  pieces  of  paper  or  card  into  the 
and  Dirt.  pipes,  has  led  to  the  invention  of  a  means  of 

removing  dust  and  dirt,  admirable  in  thorough- 
ness. A  receiver,  shaped  to  suit  its  special  task,  is  passed  over 
pictures  and  their  frames,  upholstery,  carpets  or  bare  floors,  and 

through    the    flexible    pipe 
attached  to  its  handle,  dust 
and  dirt  are  borne  into  a 
reservoir    where    they    are 
caught  by   water   for  due 
removal.    Ordinary  sweep- 
ing with  a  broom,  the  usual 
Hardie  nozzle  for  painting  by  com-          wielding      of      a      feather 
pressed  air.  duster,  or  a  blast  of  com- 

pr^^sed  air,  but  stir  up  dust 

and  dirt  for  harmful  redistribution.  This  ""acuum"  cleaning 
method  takes  dust  and  dirt  wholly  away,  anH  with  wonderful 
celerity.  See  picture  opposite  page  164.  It  is  astonishing  to  see  a 
pound  of  fine  flour  removed  from  a  thick  carpet  in  twelve  seconds, 
leaving  behind  not  one  visible  particle.  This  plan  cleanses  carpets 
without  their  being  lifted  from  floors,  or  a  billiard  cloth  just  as  it 
stands  on  a  table.  This  service  greatly  promotes  health;  the 
further  the  physician  goes  with  his  microscope  the  more  con- 
vinced is  he  that  dust  is  one  of  the  chief  carriers  of  disease. 

Not  only  dust  but  sand  may  be  borne  when  a  breeze  rises  to  a 
gale. 


424  COMPRESSED  AIR 

In  Lyell's  Bay,  near  Wellington,  New  Zealand,  and  in  many 

other  places   throughout  the  world,  flints  have  been   found  so 

beautifully    and    symmetrically    polished    that 

Sand-blast.         they  were  at  first  believed  to  be  products  of 

art,    yet    nothing   but    wind-blown    sand    had 

given  them  form.    Fifty  years  ago  globes  for  gas  jets  were  frosted 

by  a  handful  of  sand  quickly  thrown  from  side  to  side  for  a  few 

minutes.  Strange  to 
say,  gunnery  was  to 
supply  the  link  to 
carry  sand  to  labors 
of  much  greater 
moment. 

General       B.       C. 
Tilghman,    of    Phila- 
delphia,      one       day 
Vacuum  renovators  for  carpets  and  upholstery,      noticed       the      much 

worn  touch-hole  of  an 

old  bronze  cannon.  He  felt  sure  that  the  wear  had  been  due  not 
so  much  to  outflowing  gases  as  to  bits  of  unburnt  powder  driven 
out  at  each  discharge,  identifying  this  abrasion  with  the  roughen- 
ing of  glass  in  windows  facing  sandy  shores  of  the  sea.  In  1870 
he  began  experiments  by  blowing  sand  jets  with  a  fan,  soon  dis- 
covering that  he  had  hit  upon  a  cheap  and  easy  means  of  frosting 
glass,  carving  stone,  and  scouring  castings.  He  was  astonished 
to  find  that  sand  readily  pierced  materials  harder  than  itself,  as 
corundum  and  toughened  steel.  To-day  the  sand-blast  executes 
many  new  tasks :  it  resurfaces  stone  buildings  which  have  become 
discolored  and  grimy ;  it  cleanses  metallic  surfaces  for  the  welder, 
the  electroplater,  the  enameler;  it  renews  files  and  rasps;  it  re- 
moves scale  from  boilers,  paint  and  rust  from  steel  bridges  and 
other  structures.  The  apparatus  manufactured  by  Mr.  C.  Druck- 
lieb,  of  New  York,  designed  much  in  the  form  of  a  steam  injector, 
employs  air  at  a  pressure  of  about  twenty  pounds  to  the  square 
inch. 

Compressed  air  is  at  work  on  so  large  a  scale  that  its  economical 
production  and  use  are  matters  of  consequence.  Mechanism  for 
joth  purposes,  of  the  best  design,  involves  a  few  simple  prin- 


SAND-BLAST 


425 


ciples.     Suppose  we  have  a  cylinder,  fourteen  inches  long,  and 
that  with  a  piston  we  force  the  contained  air  within  one  inch  of 
its  base,  so  as  to  occupy   1/14  of  its  original 
volume.     This  act  of  compression,  which  we    Air  Compressors. 
will  imagine  to  be  all  but  instantaneous,  will 
heat  the  air  through  613°  Fahr.,  so  that  if  at  60°  when  the  opera- 
tion begins,  the  air  will  be  673°  at  the  end.    Suppose,  further,  that 
this  air  parts  with  no  heat  to  sur- 
rounding metal,  and  that  the  piston 
moves  without   friction ;  the  com- 
pressed air  on  being  allowed  to  ex- 
pand will  return  all  the  work  ex- 
pended in  compression,  and  resume 
its  first  temperature,  60°.     If  air 
would  serve  us  in  this  ideal  way, 
we  would  have  an  agent  with  all 
the  good  points  of  steam  and  none 
of  its  drawbacks.     In  actual  prac- 
tice several  items  left  out  of  our 
imaginary  picture  must  be  reckoned 
with.     Air  heated  in  compression 
quickly  warms  surrounding  masses 
and  has  to  be  cooled  when  sent  off 
on    distant    errands,    losing    much 
working  power  in  the  process.  The 
very  act  of  compression  retards  it- 
self :  the  air,  because  heated,  has 
additional  elasticity  for  the  com- 
pressor to  overcome. 

Plainly,  the  engineer  should  begin  by  sending  into  his  com- 
pressor air  as  cool  as  possible,  and  during  compression  he  should 
keep  the  temperature  of  the  air  as  low  as  he  can.  Moderate  pres- 
sures, to  fifty  pounds  per  square  inch  or  so,  may  well  be  effected 
at  a  single  stroke,  the  air  as  it  issues  from  the  compressing  cyl- 
inder passing  through  pipes  immersed  in  cold  water,  a  similar 
chilling  stream  being  sent  around  the  cylinder  walls  themselves. 
This  air  at  fifty  pounds,  duly  cooled,  may  now,  if  we  wish,  be 
brought  to  say  100  pounds  pressure  in  a  second  cylinder ;  its  out- 


Injector  sand-blast. 
C.  Drucklieb,  New  York. 


426 


COMPRESSED  AIR 


put  is  in  turn  cooled  as  before  by  conveyance  through  pipes 
bathed  in  cold  water.  The  more  thorough  the  cooling,  the  less 
moisture  will  the  air  contain  to  give  trouble  afterward  by  con- 
densing in  pipes  or  machinery.  If  a  pressure  higher  than  100 

pounds  to  the  square  inch  is 
in  request,  a  third  compres- 
sor may  be  linked  to  the 
second.  In  some  installa- 
tions, where  extreme  pres- 
sures are  attained,  four-fold 
apparatus  is  employed;  its 
chief  economy  rests  in  cool- 
ing the  air  at  four  distinct 
stages,  greatly  diminishing 
the  work  which  otherwise 
would  have  to  be  wastefully 
done. 

With  the  energy  of  steam 
economically  converted  into 
the  energy  of  compressed 
air,  the  engineer  sends  his 
new  servant  as  far  as  he 
pleases.  Let  us  imagine  that 
a  mile  off  he  wishes  to  drive 


Vertical  receiver,  inter-  and  outer- 
cooler.     Ingersoll-Rand  Co., 
New  York. 


a  gang  of  saws.  He  will 
soon  notice  that  the  exhaust 
pipe  is  very  cold,  and  if  the 

compressed  air  was  not  well  dried  as  produced,  its  moisture  will 
now  be  deposited  not  as  water  merely,  but  as  frost  to  check  the 
machinery.  This  is  because  air,  like  steam,  falls  in  temperature 
as  it  expands  at  work;  that  fall  measuring  the  heat-equivalent 
of  the  work  performed.  For  the  chill  which  the  engineer  ob- 
serves, he  has  a  simple  remedy ;  he  surrounds  the  air  pipe,  as  it 
enters  its  machinery,  with  a  small  heater,  fed  with  coke,  coal,  or 
oil.  At  once  all  frost  vanishes,  and  the  air  with  added  elasticity 
is  vastly  more  effective  than  before.  By  no  other  means  can  so 
much  work  be  won  from  fuel  as  through  this  device.  In  some 


A  CENTRALIZED  AIR  PLANT        427 

cases  a  heater  has  yielded  1.25  horse  power  for  an  hour  in  re- 
turn for  each  pound  of  coal  it  has  burned. 

In  producing  compressed  air,  inventors  step  by  step  have  kept 
in  view  the  best  steam  practice.  It  was  long  ago  observed  that 
working  steam  when  wholly  expanded  in  one  cylinder  chills  itself, 
imparting  its  chill  to  the  cylinder  walls  so  that  they  seriously  cool 
the  next  charge  of  steam,  lowering  its  value  for  motive  power. 
In  a  multiple  expansion  engine  of  four  successive  cylinders,  each 
in  turn  receives  the  steam,  which  with  thorough  jacketing  is  main- 
tained at  the  highest  temperature  possible.  Keeping  to  converse 
lines  the  compressor  divides  its  task  into  stages,  at  each  of  which 
a  desired  change  of  temperature  can  be  easily  effected.  With 
steam  this  change  consists  in  adding  heat ;  with  compressed  air  it 
consists  in  abstracting  heat. 

Thirty  miles  from  Cleveland,  at  North  Amherst,  Ohio,  is  the 
largest  sandstone  quarry  in  the  world.    Its  owners,  the  Cleveland 
Stone   Company,   in   their   original   plant  em- 
ployed steam  from  no  fewer  than  forty-nine        A  Centralized 
t   M  11  i  •  -11-  1-11  j  Air  Plant. 

boilers,    all    machinery,    including    drills    and 

channelers,  being  driven  by  steam.  In  January,  1904,  this  was 
replaced  by  a  centralized  air  plant  which  has  resulted  in  marked 
economy.  In  the  power-house  four  water-tube  boilers,  each  of  257 
horse-power  rated  capacity,  drive  compound  compressors  which 
deliver  air  at  about  100  pounds  pressure.  This  air,  duly  piped,  is 
distributed  to  drills,  channelers,  hoists,  pumps,  saws,  grindstones, 
forge  fires,  and  so  on.  Economies,  familiar  in  electrical  centraliza- 
tion, are  here  paralleled  in  an  interesting  way.  In  the  working 
day  not  a  moment  is  wasted.  When  the  whistle  blows  the  full 
working  pressure  is  ready  to  begin  work  and  maintain  duty  until 
night.  There  is  no  fluctuation  of  pressure  due  to  careless  boiler 
attendance ;  no  wheeling  coal  or  water  barrels  to  keep  pace  with 
advancing  channelers.  Some  of  the  old  boilers,  discarded  from 
steam  service,  are  used  as  air  receivers,  these  and  other  reservoirs, 
together  with  the  pipe  line  itself,  unite  their  immense  storage 
capacity  so  that  throughout  the  day  there  is  no  peak  load.  In- 
cidentally the  new  plant  renders  the  quarry  free  from  smoke-laden 
steam  such  as  of  old  darkened  its  air  and  soiled  its  output.  Fuel 


428  COMPRESSED  AIR 

and  labor  under  this  system  were  reduced  one  half  when  a  month 
of  the  old  service  was  compared  with  a  month  of  the  new.  In 
one  case  steam  is  used  for  power  outside  of  the  main  plant.  Close 
to  the  power-house  is  a  mill  where  eleven  gang  saws  are  driven 
by  a  steam  engine  of  175  horse-power.  The  nearness  of  this  en- 
gine to  the  boilers  ensures  a  somewhat  higher  economy  than  if 
compressed  air  were  employed.  Here,  as  everywhere  else,  the 
engineer  engages  whatever  servant  will  do  good  work  at  the 
lowest  wages. 

By  all  odds  the  most  important  use  of  compressed  air  is  that 
developed  by  Mr.  George  Westinghouse,  of  Pittsburg,  in  his  auto- 
matic  brakes    for   railroads.     For   each   loco- 
Westinghouse        motive  he  provides  an  air  compressor  which 
Air  Brakes          fillg  jn  the  enRme  jtseif  an(j  beneath  each  car,  a 
and  Signals.  °  . 

reservoir  of  compressed  air.     Every  reservoir 

aboard  a  long  train  in  rapid  motion  may  at  the  same  instant,  by  a 
touch  from  the  engine-runner,  actuate  the  brakes  so  as  to  stop 
the  train  in  the  shortest  possible  time.  This  invention  has  accom- 
plished more  for  the  safety  of  quick  railroad  travel  than  any  other 
device ;  no  wonder,  then,  that  Westinghouse  brakes  are  in  all  but 
universal  use.  They  are  now  being  adopted  for  trolley-cars  wh;ch 
often  require  to  be  stopped  in  the  briefest  possible  period.  The 
Westinghouse  Company  builds  and  installs  elaborate  signal  sys- 
tems worked  by  compressed  air  and  electricity.  All  these  are  de- 
scribed and  pictured  in  the  "Air  Brake  Catechism,"  by  Robert  H. 
Blackall,  published  by  N.  W.  Henley  &  Co.,  New  York.  This 
book  is  constantly  appearing  in  new  editions,  of  which  the  reader 
should  procure  the  latest. 


CHAPTER  XXIX 

CONCRETE  AND  ITS  REINFORCEMENT 

Pouring  and  ramming  are  easier  and  cheaper  than  cutting  and  carving  .  .  . 
Concrete  for  dwellings  ensures  comfort  and  safety  from  fire  .  .  . 
Strengthened  with  steel  it  builds  warehouses,  factories  and  bridges  of 
new  excellence. 

STONE  and  wood  in  the  builder's  hands  require  skill  and 
severe  labor  for  their  shaping;  vastly  simpler  and  easier  is 
the  task  of  molding  a  wall  from  wet  clay,  or  other  semi-plastic 
material.  It  was  long  ago  discovered  that  certain  mixtures  of 
clay  and  sand,  duly  mingled  and  burned,  became  as  hard  as  stone. 
To  this  discovery  we  owe,  among  other  arts,  that  of  brick-making. 
In  joining  brick  to  brick,  or  stone  to  stone,  a  mortar  of  uncommon 
strength  was  used  by  the  Romans.  All  by  itself,  when  laid  a  little 
at  a  time,  it  formed  a  strong  and  lasting  structure.  Then  it  oc- 
curred to  some  inventive  builder,  Why -not  save  mortar  by  throw- 
ing into  it  gravel  and  bits  of  broken  stone?  He  accordingly 
reared  a  wall  of  what  we  should  now  call  rude  concrete,  whose 
lineal  descendant  to-day  is  a  semi-plastic  mass  of  Portland 
cement,  sand,  and  gravel  or  broken  stone,  together  with  the  neces- 
sary water.  Its  use  allows  the  ease  and  freedom  of  pouring,  while 
affording  structures  with  all  the  "strength  of  stone  or  brick. 

For  much  of  the  early  work  lime  and  sand  were  mixed  to  make 
a  mortar  of  the  usual  kind,  in  which  stone  or  gravel  was  em- 
bedded. Afterward  it  was  found  that  volcanic  ashes,  such  as 
those  of  Puzzuoli  near  Naples,  formed  with  lime  a  compound 
which  resisted  water  and  was  therefore  suitable  for  structures 
exposed  to  damp  or  wet.  In  the  middle  ages  concrete  was  em- 
ployed throughout  Europe,  after  the  Roman  fashion,  for  both 

429 


430  CONCRETE 

foundations  and  walls.  In  walls  it  was  usually  laid  as  a  core 
faced  with  stone  masonry,  large  stones  often  being  embedded  in 
the  mass.  About  1750,  while  building  the  third  Eddystone  Light- 
house, John  Smeaton  discovered  that  a  limestone  which  con- 
tained clay,  when  duly  burnt,  cooled,  ground,  and  wetted,  hard- 
ened under  water,  was  indeed  a  natural  cement,  by  which  name  it 
is  still  known.  Deposits  suitable  for  the  direct  manufacture  of 
natural  cement  were  in  1818  discovered  in  Madison  and  Onon- 
daga  Counties,  New  York,  by  Canvass  White,  an  engineer  who 
used  this  cement  largely  in  building  the  Erie  Canal.  Natural 
cement  has  a  powerful  rival  in  Portland  cement,  due  to  Joseph 
Aspdin,  of  Leeds,  who  in  1824  mixed  slaked  lime  and  clay,  highly 
calcined.  The  resulting  clinker  when  ground,  and  only  when 
ground,  unites  with  water,  the  strength  of  the  union  increasing 
with  the  fineness  of  the  grinding.  Because  this  product  looks 
like  Portland  stone,  much  used  in  England,  it  was  given  the 
name  of  Portland  cement.  The  raw  materials  suitable  for  making 
it  are  widely  distributed  throughout  North  America,  much  more 
widely  than  those  from  which  natural  cement  may  be  had.  This 
is  the  principal  reason  why  Portland  cement  is  now  produced  in 
the  United  States  in  about  six- fold  the  quantity  of  natural  cement. 

So  rapidly  has  concrete  grown  in  public  favor  with  American 
builders  that  in  1905  they  used  seven-fold  as  much  as  in  1890. 
It  has  been  widely  adopted  for  pavements,  as  at  Bellefontaine, 
Ohio ;  for  breakwaters,  as  at  Galveston  and  Chicago ;  for  tunnels, 
as  in  more  than  four  miles  of  the  New  York  Subway.  The 
foundations  beneath  the  power-house  of  the  Interborough  Rapid 
Transit  Company,  New  York,  required  80,000  cubic  yards ;  for 
the  new  station  of  the  Pennsylvania  Railroad  Company,  New 
York,  a  much  greater  quantity  is  being  employed;  in  their  turn 
these  figures  will  be  far  exceeded  by  the  needs  of  the  new  Croton 
Dam  for  the  water  supply  of  New  York,  and  the  Wachusett 
Dam  for  the  water  supply  of  Boston. 

Concrete  has  long  been  adopted  for  a  variety  of  less  ambitious 
purposes.  At  St.  Denis,  near  Paris,  it  was  many  years  ago 
molded  into -a  bridge  of  modest  span.  It  has  formed  thousands 
of  dwellings  in  factory  and  mining  villages  and  towns,  as  well  as 
many  villas  of  handsome  design.  It  is  particularly  well  adapted 


WHY  DESIRABLE 


431 


for  silos,  as  here  illustrated.1  All  this  expansion  of  an  old  art 
has  been  stimulated  by  a  steady  reduction  in  the  price  of  Port- 
land cement,  and  by  constant  improvement  in  its  quality.  As  the 
manufacture  has  expanded,  its  standards  have  risen,  its  ma- 
chinery has  become  more  economical  and  trustworthy  in  results. 
While  the  cost  of  concrete  has  thus  been  lowered  by  a  fall  in  the 
price  of  cement,  the  wages  of  bricklayers  and  stone-masons  have 


Concrete  silo  foundation,  Bricelyn,  Minn. 

advanced,  adding  a  new  reason  for  building  in  concrete,  since  it 
requires  in  execution  but  little  skilled  labor.  The  good  points  of 
concrete  are  manifold ;  it  forms  a  strong,  fire-resisting,  and  damp- 
proof  structure.  For  mills  and  factories  another  item  of  gain  is 
that  it  forms  a  unit  such  as  might  be  hewn  out  of  a  single  huge 
rock,  vibrating  machinery  therefore  affects  it  much  less  than  it 
does  an  ordinary  building.  At  the  same  time  its  walls  and  floors 
obstruct  sound,  conducing  to  quiet.  Concrete  must  be  honestly 
made  and  used,  otherwise,  just  as  in  the  case  of  rubbishy  bricks, 

JThe  illustration  of  a  silo  and  its  foundation  are  taken  by  permission 
from  "Concrete  Construction  about  the  Home  and  on  the  Farm,"  copy- 
right 1905  by  the  Atlas  Portland  Cement  Co.,  30  Broad  St.,  New  York. 
This  book  of  127  pages,  fully  illustrated,  with  instructions  and  specifica- 
tions, is  sent  gratis  on  request 


432 


CONCRETE 


ill  laid,  it  may  tumble  down  from  its  own  weight.  And  further- 
more it  is  necessary  to  recognize  how  widely  concretes  of  diverse 
composition  vary  in  strength  and  durability.  There  should  be  a 


Concrete  silo,  Gedney  Farms,  White  Plains,  N.  Y. 

careful  adaptation  in  each  case  of  quality  to  requirement.  Con- 
crete walls,  as  first  produced,  had  a  forbidding  ugliness;  this  is 
being  remedied  by  sur facings  of  pleasant  neutral  tones.  A  well 
designed  residence  executed  in  concrete  at  Fort  Thomas,  Ken- 
tucky, is  shown  opposite  this  page. 

In  Mr.  Edison's  judgment  a  vast  field  awaits  the  concrete  in- 
dustry in  building  small,  cheap  dwellings.    He  once  said  to  me, 


HOW  MANUFACTURED  433 

as  he  spoke  of  his  cem'ent  mill,— "What  I  want  to  see  is  an  archi- 
tect of  the  stamp  of  Mr.  Stanford  White  of  New  York  take  up 
this  material.  Let  him  design  half  a  dozen  good  dwellings  for 
working  people,  all  different.  Each  set  of  molds,  executed  in 
metal,  would  cost  perhaps  $20,000.  Such  dwellings  could  be 
poured  in  three  hours,  and  be  dry  enough  for  occupancy  in  ten 
days.  A  decent  house  of  six  rooms,  as  far  as  the  shell  would  go, 
might  cost  only  three  hundred  dollars  or  so.  It  would  be  stereo- 
typy  over  again  and  the  expense  for  the  models  would  disappear 
in  the  duplications  repeated  all  over  the  country." 

Concrete  is  now  supplied  to  builders  in  blocks,  usually  hollow 
and  much  larger  than  bricks.  When  cast  in  sand  they  look  like 
stone.  Of  course,  subjected  as  they  are  to  more  than  ordinary 
stresses,  their  production  demands  special  care.  The  methods, 
therefore,  which  are  adopted  in  manufacturing  these  blocks  may 
be  taken  as  the  best  practice  in  the  industry  broadly  considered. 
Says  Mr.  H.  H.  Rice,  of  Denver :— "The  sand  employed  should 
be  sharp,  silicious  and  clean.  The  gravel  used  should  contain  a 
fair  proportion  of  as  large  sizes  as  can  be  advantageously  em- 
ployed in  the  particular  machine  used.  Where  gravel  is  not 
available,  crushed  stone  takes  its  place.  Care  should  be  exercised 
to  obtain  stone  as  strong  as  the  mortar.  What  proportions  of 
san  1,  gravel  and  broken  stone  should  be  mixed  together  is  a 
question  determined  by  the  extent  of  their  voids :  these  may  vary 
from  one  third  to  one  half  the  whole  volume.  Assuming  that 
we  have  to  deal  with  the  larger  fraction,  a  mixture  of  i  cement, 

2  sand,  4  gravel,  should  be  employed;  this  is  classified  as  the 
lowest  grade  of  fat  mixture.    At  times  a  lean  mixture,  I  cement, 

3  sand,    5   gravel,   might   be   advantageously   adopted.     Where 
gravel  or  broken  stone  is  not  used,  the  proportion  of  cement  to 
sand  should  be  as   I  to  4.     A  fat  mixture  has  greater  tensile 
strength  than  a  lean  mixture,  but  resistance  to  compression  de- 
pends upon  a  thorough  filling  of  voids.     A  lean  mixture  thor- 
oughly worked,  proves  more  satisfactory  than  a  fat  mixture  with 
hasty  and  indifferent  handling.     With  any  mixture  success  is  at- 
tained  only  by   completely   coating   every   grain   of   sand   with 
cement,  and  every  piece  of  stone  or  gravel  with  the  sand-cement 
mortar.     (See  Mr.  Um stead's  results,  page  240.) 


434 


CONCRETE 


In  producing  concrete  blocks  there  are  three  different 
methods,  tamping,  pressing,  and  pouring,  each  adapted  to  a  par- 
ticular mixture  for  a  special  kind  of  work.  Two-piece  walls,  de- 
vised in  1902,  deserve  a  word  of  description.  The  pressed  blocks 
of  which  they  are  built  show  the  new  freedom  conferred  by  con- 
crete as  a  building  material.  Each  block  has  a  long  right-angle 
arm  extending  inward  from  the  middle,  and  a  short  arm  extend- 
ing from  each  end.  In  laying  the  blocks  in  a  wall  no  portion  of  a 


Wall  of  two-piece  concrete  blocks. 
American  Hydraulic  Stone  Co.,  Denver. 


block  extends  through  the  wall.  By  leaving  the  exterior  vertical 
joints  open  to  afford  a  free  circulation  of  air,  no  part  of  a  block 
on  one  side  of  the  wall  touches  any  block  from  the  opposite  side ; 
this  prevents  the  passage  of  moisture  and  produces  in  effect  two 
walls,  tied  by  the  overlapping  arms  or  webs  in  alternate  courses 


A  BACKBONE  ADDED  435 

and  affording  in  its  bond  a  great  resistance  to  lateral  stresses. 
Blocks  in  other  forms  equally  useful  are  steadily  gaining 
popularity.1 

Concrete,  although  widely  available  to  the  builder,  is  in  many 
cases  a  material  he  cannot  employ.  For  a  store-house,  thickness 
of  wall,  ensuring  an  equable  temperature,  is  an  advantage;  for 
an  office-building,  reared  on  costly  ground,  this  thickness  is  out 
of  the  question.  Beams,  too,  cannot  have  much  length  in  a 
material  which  is  only  one  tenth  as  strong  in  tensile  as  in  com- 
pressive  resistance.  Clearly  the  scope  for  concrete  by  itself  was 
to  be  limited  unless  it  could  find  a  partner  able  to  confer  strength 
while  adding  but  slight  bulk.  An  experiment  of  the  simplest  was 
to  be  the  turning  point  in  a  great  industry. 

Concrete,  as  one  of  its  minor  uses,  had  often  been  molded  into 
tubs  for  young  trees  and  shrubs.  In  1867,  Joseph  Monier,  a 
French  gardener,  in  using  tubs  of  this  kind 

found  them  heavy  and  clumsy.     By  way  of       Concre'e  Rcin' 

forced  by  a 
improvement  he  built  others  in  which  he  em-         Backbone  of 

bedded   iron    rods   vertically   in   the   concrete,       Steel.    Joseph 
securing  thus  a  strong  frame-work  which  per-         Monier,  the 
mitted  him  to  use  but  little  concrete,  and  make  loneer. 

tubs  comparatively  light  and  thin.  Monier  was  not  a  man  to  rest 
satisfied  with  a  single  step  in  a  path  of  so  much  promise.  Before 
his  day  builders  had  joined  concrete  and  metal,  but  without  rec- 
ognizing the  immense  value  of  the  alliance.  He  proceeded  to 
build  tanks,  ponds,  and  floors  of  his  united  materials,  at  length 
rearing  bridges  of  modest  proportions.  His  work  attracted  at- 
tention in  Germany  and  Austria,  as  well  as  at  home  in  France, 
so  that  soon  reinforced  concrete,  as  it  was  called,  became  a  serious 
rival  to  brick  and  stone.  For  two  thousand  years  and  more,  con- 
crete had  been  a  familiar  resource  of  the  builder;  to-day  with  a 
backbone  of  steel  it  fills  an  important  place  between  masonry  and 
skeleton  steel  construction,  boldly  invading  the  territory  of  both. 

1  Mr.  H.  H.  Rice's  first-prize  paper  on  the  manufacture  of  concrete 
blocks  and  their  use  in  building  construction  appeared  in  the  Cement  Age, 
New  York,  October,  1905.  Permission  to  use  his  paper  and  the  illus- 
tration here  presented,  both  copyrighted,  has  been  courteously  extended  by 
the  publishers. 


486 


REINFORCED  CONCRETE 


Reinforced  concrete  has  been  thoroughly  studied  with  regard 
to  its  properties  and  the  forms  in  which  it  may  be  best  disposed. 
Since  the  strength  of  concrete  is  usually  ten- 
Disposal  of  Steel  fold  greater  in  compression  than  in  tension, 

in  Reinforced  designs  should  be  compressive  whenever  pos- 
Concrete.  sible,  all  tensile  strains  being  carefully  com- 

mitted to  the  steel.  In  arched  bridges  the 
strains  are  chiefly  compressive,  hence  the  success  with  which  they 
are  executed  in  reinforced  concrete.  Mr.  Edwin  Thacher  of  New 
York,  eminent  in  this  branch  of  engineering,  sees  no  reason  why 
spans  of  500  feet  should  not  be  feasible  and  safe.  Some  remark- 
able discoveries  have  followed  upon  experiments  with  reinforce- 
ment diverse  in  form  and  variously  placed  within  a  mass.  To 
increase  the  strength  of  a  square  steel  bar  Mr.  E.  L.  Ransome 
twists  it  into  spiral  form ;  on  square  steel  bars  Mr.  A.  L.  Johnson 


Ransome  bar. 


places  projections;  Mr.  Edwin  Thacher  rolls  his  steel  into  sec- 
tions alternately  flat  and  round.     All  these  contours  have  large 


Corrugated  steel  bar.    St.  Louis  Expanded  Metal  Fire  Proofing  Co. 

surfaces  at  which  metal  and  concrete  adhere.     Reinforcing  bars 
designed  bv  Mr.  Julius  Kahn  and  bv  the  Hennibinue  Construc- 


Thacher  bar. 


BARS  AND  NETS 


437 


lion  Company  are  smooth,  and  slightly  bent  from  straightness  at 
intervals.     In  every  case  the  question  is,  Where  will  the  tensile 


Kahn  bar. 

strength  of  the  steel  do  most  good,  because  most  needed?     M. 
Considere  has  found  that  concrete  hooped  with  steel  wire  has 


Hennebique  armored  concrete  girder. 


1/ST#tBUTtN6  BARS 

/CARRYING  BARS 


more  than  twice  the  resistance  of  concrete  in  which  an  equal 
amount  of  steel  is  centrally  placed.  In  his  floor  constructions  M. 

Matrai  gives  steel  wires  the 
curves  they  would  take  under  a 
load.  Keeping  to  its  original 
lines  the  Monier  reinforcement  of 
to-day  consists  in  a  rectangular 
netting  of  rods  or  wires.  Some- 
what similar  is  the  expanded 
metal  backing  invented  by  Mr.  J. 
F.  Golding ;  it  is  sheet  steel  pierced 
with  parallel  rows  of  slits  which 
are  expanded  until  the  metal  as- 
sumes the  form  shown  in  an  ac- 
companying illustration.  A  lock 
woven-wire  fabric  of  galvanized 

steel  wire  is  made  by  W.  N.  Wight  &  Company,  New  York,  in 
any  desired  size  of  mesh,  with  an  ultimate  strength  of  116,000 
pounds  per  square  inch  of  metal. 


Ji  .1 

i 

(1 

ll 

1 

1 

U        J        U        U        U 

Monier  netting. 

438 


REINFORCED  CONCRETE 


For  piling,  reinforced  concrete  is  extensively  used.  Its  inde- 
pendence of  moisture,  its  exemption  from  the  ravages  of  the 
teredo,  render  it  much  preferable  to  timber  for  marine  work. 


Expanded  metal  diamond  lath. 


Reinforced  concrete,  like  every  other  new  building  material, 
has  called  forth  ingenuity  in  many  ways.  When, 
for  instance,  a  factory  is  to  be  reared  much  in- 
ventive carpentry  is  required 
to    plan    and    construct    the      Molds  for  Rein- 
forms,  or  molds,  into  which      forced  Concrete, 
the  liquid  concrete  is  to  be 
poured  around  the  steel  skeletons.     The  foot- 
ings, outside  and  inside  columns,  walls,  girders, 
beams,  floor-plates,  roofs,  and  stairs  all  require 
separate  forms,  intelligently  devised  with  a  view 
to  economy.     For  the  Ingalls  Building,  Cincin- 
nati, the  forms  cost  $5.85  per  cubic  yard  of  con- 
crete in  place.    White  pine  is  the  best  wood  for 
the  purpose ;  it  is  readily  worked  and  keeps  its 
shape  when  exposed  to  wind  and  weather.   For 
common  buildings  a  cheaper  wood,  spruce  or  fir, 
may  be  chosen ;  even  hemlock  will  serve  if  a  rough  finish  suffices. 


Tree  box  in 
expanded  steel. 


ROYAL  BANK  OF  CANADA,  HAVANA. 
Built  of  concrete.     Entrance. 


OF  THE 

UNIVERSITY 

OF 


HUGE  BUILDIXGS 


439 


Lock-woven  wire-fabric. 
W.  N.  Wight  &  Co., 
New  York. 


In  most  cases  green  lumber  is  preferable  to  dry  as  less  affected  by 
water  in  the  concrete.     In  fine  work  the  boards  of  which  the 
molds  are  made  are  oiled,  and  may 
be  used  over  and  over  again.    In  all 
tasks   a   strict   rule   is   that   the   re- 
inforcing metal  be  properly  placed 
and    remain    undisturbed    as    work 
proceeds. 

The  Pugh  Power  Building, 
erected  for  manufacturing  purposes 
in  Cincinnati,  is  a  capital  example  of 
what  can  be  done  with  reinforced 
concrete.  It  is  68  feet  wide,  335 
long,  and  1 59  high ;  its  columns  are 
spaced  fourteen  to  seventeen  feet 
longitudinally,  twenty  to  twenty- 
three  feet  transversely ;  the  floors  are 

figured  to  bear  a  load  of  230  pounds  per  square  foot.  In  the  same 
city  is  the  Ingalls  Building,  for  offices,  100  by  50  feet,  and  210 
feet  high,  designed  by  Mr.  E.  L.  Ransome  of 
New  York.  Among  other  structures  of  his  Buildings  of 
design,  executed  in  the  same  material,  is  the 
St.  James  Episcopal  Church,  Brooklyn,  New 
York;  buildings  for  the  United  Shoe  Machinery  Company, 
Beverly,  Massachusetts,  and  piano  factories  for  the  Foster-Arm- 
strong Company,  Despatch,  New  York.  The  inspection  shops  of 
the  Interborough  Rapid  Transit  Company,  West  59th  Street, 
New  York,  are  also  of  reinforced  concrete:  no  wood  is  used  in 
wall  or  roof. 

Reinforced  concrete  forms  nine  bins  in  one  of  the  grain 
elevators  of  the  Canadian  Pacific  Railway  at  Port  Arthur,  On- 
tario, on  the  shore  of  Lake  Superior.  The  walls  are  nine  inches 
thick,  reinforced  horizontally  and  vertically  to  a  height  of  ninety 
feet  and  a  diameter  of  thirty  feet.  There  are  also  four  inter- 
mediate bins,  the  whole  thirteen  holding  443,000  bushels.  At 
South  Chicago  the  Illinois  Steel  Company  has  built  four  similar 
bins  for  the  storage  of  cement,  each  twenty-five  feet  in  diameter 
and  fifty  feet  high,  with  walls  five  to  seven  inches  thick. 


Reinforced 
Concrete. 


440 


REINFORCED  CONCRETE 


Many  chimneys  have  been  built  of  the  new  material;  notably 
the  chimney  for  the  Pacific  Coast  Borax  Company,   Bayonne, 
M  New  Jersey,   150  feet  high,  with  an 

interior  diameter  of  seven  feet.  These 
dimensions  are  exceeded  at  Los  An- 
geles, California,  where  a  chimney  for 
the  Pacific  Electric  Company  rises  174 
feet  above  its  foundations,  with  an  in- 
side diameter  of  eleven  feet.  Both 
structures  have  hollow  walls  of  the 
Ransome  type  reinforced  horizontally 


1 

i 

8 

B 

1 

LL 

\ 

^              A                     ^ 

12-ili 


That  reinforced  concrete  serves  to 
build  chimneys  and  flues  is  proof  of 
its  fire-resisting  quality.  Concrete  is 
a  slow  conductor  of  heat,  and  both  it 
and  steel  have  almost  the  same  slight 
expansibility  as  temperatures  rise,  so 
that  they  remain  together  in  a  fire. 
Terra  cotta,  which  expands  much 
more  than  steel  when  heated,  cracks 
off  from  the  metal  it  was  intended  to 
protect,  leaving  it  to  bend  or  fuse  in 
a  blaze.  Concrete,  furthermore,  be- 
haves well  when  its  temperature  is 
suddenly  lowered,  as  when  a  fireman 
dashes  a  stream  of  water  upon  it  at  a 
fire.  No  wonder,  then,  that  the  re- 
inforced concrete  is  more  and  more  in 
request  in  cities  as  the  material  for 
buildings  rising  higher  and  standing 
more  thickly  on  the  ground  than  did 
buildings  of  old.  In  the  great  fire  in 

San  Francisco,  April,  1906,  reinforced  concrete  withstood  ex- 
treme temperatures  much  better  than  any  other  material.  It  will 
be  largely  used  in  rebuilding  the  city. 

Frequently  the  question  is  asked,  Is  the  steel  in  reinforced  con- 


Column  form,  Ingalls 
Building,  Cincinnati.  A, 
A,  yokes.  B,  B,  spacing 
pieces.  From  "Rein- 
forced Concrete."  A.  W. 
Buel  and  C.  S.  Hill. 
Copyright,  Engineering 
Islews  Publishing  Co., 
New  York,  1904. 


LASTING  QUALITY 


441 


T£EL  frODf 


crete  liable  to  corrosion,  so  that  its  walls  are  likely  to  become  weak 
and  insecure  after  a  few  years  ?  With  careful  planning  and  faith- 
ful workmanship  the  results  prove  to  be  worthy  of  confidence. 
Professor  Charles  L.  Norton  of  Boston  has 

taken   steel,   clean   and   in   all   stages  of   cor-         Resistance  to 
.......  .      .     .  Fire  and  Rust. 

rosion,  and  embedded  it  in  stone  and  cinder 

concrete,   wet   and   dry   mixtures,    in   carbon    dioxide   and   sul- 
phurous   gases;    other    specimens    were    intermittently    exposed 
to  steam,  hot  water,  and  moist  air 
for  one  to  three  months.    Duly  pro-  3,* 

tected  by  an  inch  or  more  of  sound 
concrete  the  steel  was  absolutely 
unchanged  while  naked  steel  van- 
ished into  streaks  of  rust.  Mr.  Ran- 
some  says  that  in  tearing  up  a 
stretch  of  sidewalk  in  Bowling 
Green  Park,  New  York,  in  use 
twenty  years,  some  embedded  steel 
rods  were  found  in  perfect  condition. 
The  Turner  Construction  Company, 
of  New  York,  exposed  concrete 

blocks  in  which  steel  bars  were  embedded,  and  laid  them  on  a 
beach  at  low  tide  where  they  were  covered  by  salt  water  three 
or  four  hours  every  day;  after  nine  months'  exposure  the  blocks 
were  broken  disclosing  the  bars  free  from  rust.  Professor 
Spencer  B.  Newberry  records  that  a  water  main  at  Grenoble, 
France,  built  on  the  Monier  system,  twelve  inches  in  diameter, 
eighteen  inches  thick,  containing  a  framework  of  1/16  and  1/4 
inch  steel  rods,  was  found  perfectly  free  from  rust  after  fifteen 
years'  service  in  damp  ground.  He  also  states  that  a  retaining 
wall  of  reinforced  concrete  in  Berlin  was  examined  after  eleven 
years'  use  and  the  metal  found  uncorroded,  except  in  some  cases 
where  the  rods  were  only  0.3  or  0.4  inch  from  the  surface. 

This  waterproof  quality  of  reinforced  concrete  recommends  it 
as  a  material  for  tanks  and  reservoirs.  In  1903  a  water  tower 
was  built  at  Fort  Revere,  Massachusetts,  for  the  United  States 
Government,  ninety-three  feet  in  height,  octagonal  in  section,  en- 


Section  of  chimney 
at  Los  Angeles,  Cal. 


442 


REINFORCED  CONCRETE 


closing  a  tank  twenty  feet  wide,  fifty  feet  high,  with  walls  six 
inches  thick  at  the  bottom,  three  at  the  top,  coated  inside  with  an 
inch  of  Portland  cement.  At  Louisville,  Kentucky,  a  reservoir 
has  been  built  394  by  460  feet,  and  about 
twenty-five  feet  high.  Its  walls  and  columns 
are  concrete,  its  roof  is  in  reinforced  concrete 
disposed  as  groined  arches,  each  of  nineteen 
feet  clear  span.  A  reservoir  wholly  of  reinforced  concrete  at 
East  Orange,  New  Jersey,  is  139  by  240  feet,  with  a  height  of 


Tanks, 
Standpipes, 
Reservoirs. 


Coignet  netting  and  hook. 

22  1/3  feet.    In  the  early  days  reinforced  concrete  was  used  for 
water-pipes :  more  than  a  hundred  miles  of  such  pipes  are  now  in 


Cross-section  of  conduit,  Newark,  N.  J.    Expanded  metal   reinforcement 


BRIDGES 


443 


service  in  Paris.  Water-pipes  on  the  Coignet  system  employ  thin 
steel  rods  hooked  at  both  ends  and  curved  into  encircling  hoops. 
Other  rods  laid  lengthwise  run  through  the  hooks,  so  as  to  hold 
each  part  of  the  framework  securely  in  place.  At  Newark,  New 
Jersey,  4,000  feet  of  single  and  1,500  feet  of  double  oo-inch  con- 
duits, reinforced  with  3-inch  expanded  steel,  have  been  recenth7 
laid. 

The  material  thus  available  for  systems  of  water  supply  is  also 
impressed  into  tasks  of  sewerage.  In  Harrisburg,  Pennsylvania, 
a  sewer  of  this  kind  three  miles  long 
intercepts  all  other  sewers,  carrying 
the  whole  stream  below  the  city  to  an 
outfall  in  the  Susquehanna  River.  A 
water  culvert,  for  somewhat  similar 
duty,  may  on  occasion  be  so  heavily 
reinforced  as  to  carry  railroad  tracks 
with  safety,  as  in  a  culvert  for  a 
Western  railroad  shown  in  an  ac- 
companying figure. 

Part  of  the  New  York  Subway  is 
of  reinforced  concrete.  Steel  rods, 
about  il/4  inches  square  were  laid  at 

varying  distances  according  to  the  different  roof  loads,  from  six 
to  ten  inches  apart.  Rods  il/%  inches  in  diameter  tie  the  side 
walls,  passing  through  angle  columns  in  the 
walls  and  the  bulb-angle  columns  in  the  centre. 
Layers  of  concrete  were  laid  over  the  roof  rods 
to  a  thickness  of  from  eighteen  to  thirty  inches,  and  carried  two 
inches  below  the  rods,  imbedding  them.  For  the  sides  similar 
square  rods  and  concrete  were  used  and  angle  columns  five  feet 
apart.  The  concrete  of  the  side  walls  is  from  fifteen  to  eighteen 
inches  thick. 

At  first,   properly   enough,   reinforced   concrete   was   adopted 
with   much    caution    in   bridge-building.      To-day    hundreds   of 
bridges    in    this    material    are    doing    service 
throughout  the  world.     A  good  example  of  a  Bridges. 

small  bridge  is  that  in  Forest  Park,  St.  Louis, 
spanning  the  River  des  Peres.     A  noteworthy  design  on  a  large 
scale,  by  Professor  William  H.  Burr,  of  Columbia  University, 


Water  culvert 


New  York 
Subway. 


444 


REINFORCED  CONCRETE 


New  York,  has  been  accepted  for  the  Memorial  Bridge  to  cross 
the  Potomac  River  at  Washington.     A  centre-draw  span  of  159 


SLOPE  OF_  GffADe__  __  *HV. 


$BARS 6C.TOC. 


L'UNLKUE'. 


River  des  Peres  Bridge,  Forest  Park,  St.  Louis. 

feet  in  steel  is  to  be  flanked  on  each  side  by  three  spans  of  re- 
inforced concrete,  each  of   192   feet.     Th^se  spans  are   ribbed 


MANSION  JOWTS  7/8>T/£ffooSt  6'O"C.TOC.         , 


Memorial  Bridge,  Washington,  D.  C. 

arches,  having  a  rise  of  twenty-nine  feet,  with  their  exteriors  in 
granite  masonry.  In  arguing  for  bridges  in  reinforced  concrete, 
Mr.  Edwin  Thacher  points  out  that  under  normal  circumstances 


BRIDGES  4,4,5 

their  steel  is  not  strained  to  much  more  than  one  quarter  of  its 
elastic  limit,  so  that  a  large  reserved  strength  is  available  for 
emergencies,  while  the  structure  is  more  durable  than  a  steel 
bridge  and  ultimately  more  economical,  comparatively  free  from 
vibration  and  noise,  proof  against  tornadoes  and  fire,  and  against 
floods  also  if  the  foundations  are  protected  from  scour. 


CHAPTER  XXX 
MOTIVE  POWERS  PRODUCED  WITH  NEW  ECONOMY 

Improvements  in  steam  practice  .  .  .  Mechanical  draft  .  .  .  Automatic 
stokers  .  .  .  Better  boilers  .  .  .  Superheaters  .  .  .  Economical  condens- 
ers ...  Steam  turbines  on  land  and  sea. 

IN  every  industry  a  threshold  question  is  how  motive  power  may 
be  had  at  the  lowest  cost.     In  this  field  within  twenty  years 
wholly  new  methods  have  been  introduced,  while  old  processes 


Francis  vertical  turbine  wheel.    Allis-Chalmers  Co.,  Milwaukee. 

446 


RIVALS  OLD  AND  NEW  447 

have  been  greatly  amended.  Thanks  to  economical  water-wheels 
and  generators,  efficient  transmission,  and  motors  all  but  perfect, 
water-powers,  as  at  Niagara  Falls,  now  send  electricity  to  thou- 
sands of  distant  workshops,  to  serve  not  only  as  an  ideal  means 
of  actuation,  but  as  a  source  of  light,  heat  and  chemical  impulse. 
While  electrical  art  has  thus  been  marching  forward,  all  the  heat 
engines  have  been  improved  in  every  detail  of  construction.  New 
valve-gears,  economizers  and  superheaters,  united  with  triple-ex- 
pansion cylinders  of  the  boldest  dimensions,  worked  at  pressures 
and  speeds  greater  than  ever  before,  combine  to  make  the  best 
steam  engines  to-day  vastly  more  effective  than  those  of  a  gen- 
eration ago.  And  these  engines  are  withal  facing  the  aggressive 
rivalry  of  the  steam  turbines  devised  by  De  Laval,  Parsons  and 
Curtis,  all  much  less  heavy  and  bulky  than  engines,  simpler  to 
build  and  operate,  while  their  motion  is  continuous  instead  of  in- 
terrupted at  every  piston  stroke. 

Competing  with  steam  motors  are  the  new  gas  engines,  twice  as 
efficient  in  converting  heat  into  motive  power.  For  this  reason 
and  because  much  improvement  seems  to  be  feasible  in  their  de- 
signs, and  in  systems  for  supplying  them  with  cheap  gas,  their 
adoption  on  a  large  scale  in  the  near  future  appears  to  be  certain. 
Especially  will  this  be  the  event  should  the  turbine  principle  be 
as  successfully  applied  to  gas  as  to  steam  motors.  Already  gases 
from  coke  ovens  and  blast  furnaces,  formerly  thrown  away  or 
used  only  in  part,  are  being  employed  in  gas  engines  with  success. 

To-day  the  production  of  motive  power  largely  centres  in 
stations  so  huge  that  they  adopt  with  gain  appliances  too  elaborate 
for  use  in  small  installations.  At  the  power-house  of  the  Inter- 
borough  Rapid  Transit  Company,  New  York,  for  example,  auto- 
matic machinery  conveys  coal  from  barges  to  vast  bunkers  under 
the  roof,  an  even  distribution  being  effected  by  self-reversing 
trippers.  Twelve  of  the  furnaces  have  automatic  stokers.  Ashes 
are  removed  by  conveyors.  Lubricating  oil  is  pumped  to  high 
reservoirs  whence  it  descends  to  flush  all  the  bearings ;  it  is  then 
carried  to  filters  from  which  it  passes  to  another  round  of  duty. 
Tt  is  plain  that  the  huge  scale  of  such  a  plant  opens  new  doors  to 
ingenuity,  especially  in  the  dovetailing  of  one  service  with  an- 
other. 


448  MOTIVE  POWERS 

In  some  central  stations,  as  at  Findlay,  Ada,  and  Springfield, 
Ohio,  the  exhaust  steam  is  utilized  for  district  heating,  so  that 
the  generation  of  motive  power  is  merged  into  the  larger  field  of 
fuel  economy  treated  as  a  whole.  Where  there  is  a  profitable 
market  for  exhaust  steam  it  pays  to  use  a  group  of  engines  or 
turbines  which  are  either  non-condensing,  or  only  some  of  which 
are  condensing,  for  the  aim  is  not  simply  to  use  the  motor  which 
asks  least  fuel,  but  to  install  such  motors  and  heaters  as  together 
will  earn  most  for  the  capital  invested. 

An  experimental  quadruple-expansion  steam  engine  at  Sibley 
College,  Cornell  University,  has  consumed  but  9.27  pounds  of 

steam  of   500  pounds   pressure   per   indicated 
Steam  Engines.       horse-power,   with   a  mechanical   efficiency  of 

86.88  per  cent.  An  Allis-Chalmers  compound 
engine,  tested  December,  1905,  at  the  Subway  Power-house,  New 
York,  developed  7,300  horse-power  from  steam  at  175  pounds 
pressure  with  a  consumption  of  11.96  pounds  of  steam  per  in- 
dicated horse-power.  The  cylinders  were  not  steam  jacketed  and 
no  reheaters  were  used.  This  engine  has  two  horizontal  high 
pressure  cylinders,  42  inches  in  diameter;  and  two  vertical  low 
pressure  cylinders,  86  inches  in  diameter;  all  of  60  inch  stroke. 
The  four  cylinders  work  on  the  same  crank  pin,  with  the  effect  of 
two  cranks  at  right  angles  to  each  other  in  superseded  designs. 
A  similar  engine,  less  powerful,  is  shown  opposite  this  page. 

At  this  point  let  us  put  back  the  clock  a  little  that  we  may  un- 
derstand why  tallness  in  chimneys  is  much  less  in  vogue  for  steam 

plants  than  formerly,  and  why  this  change  is 
Mechanical          found  to  be  well  worth  while.  A  device  at  least 

two  centuries  old  is  the  smoke- jack,  of  which  a 
specimen  lingers  here  and  there  in  the  museums  and  curiosity 
shops  of  England.  The  rotary  motion  of  its  vanes,  due  to  the 
upward  draft  from  a  kitchen  fire,  was  employed  to  turn  a  joint  of 
meat  as  it  roasted  in  front  of  the  coals.  To-day  the  successors  of 
this  primitive  heat-mill  are  the  cardboard  or  mica  toys  which, 
fastened  to  a  stove-pipe,  or  close  to  a  lamp  chimney,  set  at  work 
a  carpenter  with  his  saw,  a  laundress  with  her  sad-iron,  and  so 
on.  These  playthings  show  us  the  simplest  way  in  which  heat  can 
yield  motive  power ;  because  simplest  it  prevails  almost  uni- 


5000  HORSE-POWER  ALLIS-CHALMERS  STEAM  ENGINE, 

ST.  Louis  EXPOSITION,  1904. 
Horizontal  and  vertical  cylinders  united  to  the  same  crank  pin. 


MECHANICAL  DRAFT 


440 


versally,  and  yet  it  is  wasteful  in  the  extreme.  Nobody  for  a 
moment  would  think  of  putting  a  wheel  like  that  of  a  smoke-jack 
in  a  chimney  so  that  the  rising 
stream  of  hot  gases  might 
drive  a  sewing-machine  or  a 
churn,  and  yet  for  a  task  just 
as  mechanical,  namely,  the 
pushing  upward  a  chimney 
current  itself,  the  heating  that 
current  to  an  extreme  tem- 
perature is  to-day  the  usual 
plan.  Under  good  design  the 
gases  of  combustion  are  ob- 
liged to  do  all  the  work  that 
can  be  squeezed  out  of  them ; 
then  and  only  then  they  are 
sent  into  the  chimney.  What 
if  their  temperature  be  so  low, 
comparatively,  that  their  rise  Smoke-jack, 

in  the  stack,  if  left  to  them- 
selves, is  slow  as  compared  with  the  rise  in  another  stack  of 
gases  300°  hotter?  One  hundredth  part,  or  even  less,  of  the 
saved  heat  when  applied  through  an  engine  to  a  fan  will  ensure 
as  quick  a  breeze  through  the  grate-bars  as  if  the  chimney  gases 
were  wastefully  hot,  and  this  while  the  chimney  is  but  one  eighth 
to  one  fourth  as  tall  as  an  old-fashioned  structure.  This  is  the 
reason  why  mechanical  draft  is  now  adopted  far  and  wide  in 
factories,  mills  and  power-houses.  The  advantages  which  follow 
are  manifold :  the  plant  is  rendered  independent  of  wind  and 
weather,  inferior  fuels  are  thoroughly  and  quickly  consumed,  at 
times  of  uncommon  demand  a  fire  can  be  easily  forced  so  as  to 
increase  the  duty  of  the  boilers.  To-day  in  the  best  practice  the 
feed  water  for  the  boilers  is  heated  by  the  furnace  gases  just  be- 
fore they  enter  the  stack ;  the  piping  for  this  purpose,  formed  into 
coils  known  as  economizers,  checks  the  chimney  draft.  This 
checking  is  readily  overcome  by  mechanical  draft,  leaving  the 
engineer  a  considerable  net  gain  as  fan  and  economizer  are  united. 
One  incidental  advantage  in  modern  plants  of  sound  design,  and 


450  MOTIVE  POWERS 

good  management,  is  that  they  send  forth  but  little  smoke  or  none 
at  all.  With  thorough  combustion  no  smoke  whatever  leaves  the 
stack. 

The  avoidance  of  smoke  is  promoted  by  the  use  of  well  de- 
signed mechanical  stokers :  two  of  the  best  are  the  Roney  and 
the  Jones  models.    The  Jones  apparatus  forces 

its  fuel  int°  the  fire  fr°m  beneath>  so  that  its 
gases,   passing  upward  through  blazing  coal, 

are  thoroughly  consumed. 

In  large  plants  the  boilers  are  usually  of  the  water-tube  variety, 
working  at  high  pressures  which  may  be  increased  at  need.  Mr. 
Walter  B.  Snow  says  i1— "Until  the  recent  past 
Boilers.  the  steam  generator  or  boiler  and  the  manner 

of  its  operation  received  far  less  attention  than 
they  deserved.  Although  under  the  best  conditions  over  80  per 
cent,  of  the  full  calorific  value  of  the  fuel  may  be  utilized  in  the 
production  of  steam,  this  high  standard  is  seldom  reached  in 
ordinary  practice.  Mr.  J.  C.  Hoadley  showed  an  efficiency  of 
nearly  88  per  cent,  in  his  tests  of  a  warm-blast  steam-boiler 
furnace  with  air-heaters  and  mechanical  draft,  while  Mr.  W.  H. 
Bryan  has  reported  eighty-six  tests  conducted  under  common 
conditions  with  ordinary  fuel,  upon  boilers  of  various  types,  which 
indicate  an  average  efficiency  of  only  58  per  cent.,  and  have  a 
range  between  a  minimum  of  34.6  per  cent,  obtained  with  a  small 
vertical  boiler,  and  a  maximum  of  81.32  per  cent,  with  a  water- 
tube  boiler  of  improved  setting.  The  possibilities  of  increased 
economy  in  ordinary  boiler  practice  are  thus  clearly  evident." 

A  cardinal  improvement  in  steam  engineering  of  late  years  has 

been  in  perfecting  superheaters;  this  advance  owes  much  to  the 

mineral  oils  now  available   for  lubrication  at 

Superheaters.  temperatures  which  may  be  as  high  as  675° 
Fahr.  As  steam  expands  to  perform  work  it 
falls  in  temperature  and  much  of  it  condenses  as  water,  with 
marked  loss  of  efficiency,  with  harm  to  its  containers  by  severe 
hammering.  A  superheater  avoids  this  trouble  by  so  raising  the 
initial  temperature  of  the  steam  that  condensation  either  ceases 

1  In  his  "Steam  Boiler  Practice."    New  York,  John  Wiley  &  Sons,  1904. 
$3.00. 


SUPERHEATERS 


451 


altogether  or  is  much  lessened.  The  apparatus  is  usually  a  nest 
of  tubes  placed  in  the  fire-box  close  to  the  boiler;  or,  the  tubes 
may  be  heated  by  a  fire  of  their  own,  away  from  the  boiler.  The 
Schmidt  superheater  has  long,  parallel  bent  tubes,  connecting 
two  parallel  headers.  It  may  be  directly  applied  to  locomotive 


Longitudinal  section     Cross-sec-  Horizontal  see- 

on  a,  b.  tion  on  c,  d.  tion  on  e,  f. 

Schmidt  superheater. 


boilers  without  essential  modification,  and  without  checking  the 
draft.  On  the  Canadian  Pacific  Railway  about  two  hundred 
simple  locomotives  have  been  provided  with  superheaters,  lower- 
ing the  coal  consumption  to  87,  85,  83  and  as  little  as  76  per  cent, 
in  comparison  with  compound  engines  having  no  superheaters. 
At  St.  Louis  in  1904  the  Pennsylvania  Railroad  conducted 
elaborate  tests  of  diverse  locomotives.  The  most  economical 
compound  engine  each  hour  used  18.6  pounds  of  ordinary  satu- 
rated steam  per  indicated  horse-power.  Aided  by  a  superheater 
this  consumption-  was  reduced  to  16.6  pounds,  a  saving  of  10.75 
per  cent.  See  page  241.  In  Germany  portable  steam  engines  of 
150  to  220  horse-power,  superheating  their  steam  150°  to  170° 
Centigrade  above  the  temperature  of  saturation  have,  in  compound 
types,  reduced  their  demand  for  steam  to  12.47  pounds  per  horse- 
power hour  and,  in  a  triple-expansion  model,  to  9.97  pounds.  In 
all  cases  the  steam  pipe  takes  the  shortest  possible  path  between 
its  superheater  and  its  cylinder. 


452  MOTIVE  POWERS 

By  an  improved  design  Professor  R.  L.  Weighton  of  Arm- 
strong College,  Newcastle-on-Tyne,  has  doubled  the  efficiency  of 
the  surface  condenser,  and  reduced  its  con- 
Improved  sumption  of  water  44  per  cent.  In  his  ap- 
paratus the  condensing  water  enters  at  the  base, 
and  leaves  at  the  top,  after  several  circuits  instead  of  but  two  as 
in  the  ordinary  condenser.  This  new  apparatus  is  drained  off  in 
sections,  instead  of  allowing  the  condensed  steam  to  accumulate 
at  the  bottom,  as  in  common  practice.  This  sectional  drainage  is 
effected  by  dividing  the  interior  into  diaphragms  somewhat  in- 
clined to  the  horizontal,  so  that  the  water  of  condensation  is  re- 
moved as  fast  as  formed  and  does  not  flow  from  the  upper  tubes 
over  those  beneath.  The  gain  in  this  arrangement  arises  from 
the  fact  that  the  greater  part  of  the  condensation  takes  place  in 
the  upper  part  of  a  condenser,  where  the  steam  impinges  first 
upon  the  tubes.  The  Weighton  apparatus,  in  conjunction  with 
dry  air-pumps,  shows  a  condensation  of  36  pounds  of  steam  per 
square  foot  of  surface  per  hour,  with  a  reduction  of  pressure  to 
one  twentieth  of  barometric  pressure  (i^  inches  as  compared 
with  30) ,  using  as  condensing  water  28  times  as  much  as  the  feed 
water,  at  an  inlet  temperature  of  50°  Fahr. 

For  a  long  time,  and  well  into  the  nineteenth  century,  water  was 
lifted  by  pistons  moving  in  cylindrical  pumps.  Meantime  the 
turbine  grew  steadily  in  favor  as  a  water- 
Steam  Turbines.  motor,  arriving  at  last  at  high  efficiency.  This 
gave  designers  a  hint  to  reverse  the  turbine 
and  use  it  as  a  water  lifter  or  pump  :  this  machine,  duly  built,  with 
a  continuous  instead  of  an  intermittent  motion,  showed  much 
better  results  than  the  old-fashioned  pump.  The  turbine-pump 
is  accordingly  adopted  for  many  large  waterworks,  deep  mines 
and  similar  installations.  This  advance  from  to-and-fro  to  rotary 
action  extended  irresistibly  to  steam  as  a  motive  power.  It  was 
clear  that  if  steam  could  be  employed  in  a  turbine  somewhat  as 
water  is,  much  of  the  complexity  and  loss  inherent  in  reciprocating 
engines  would  be  brushed  aside.  A  pioneer  inventor  in  this  field 
was  Gustave  Patrick  De  Laval,  of  Stockholm,  who  constructed 
his  first  steam  turbine  along  the  familiar  lines  of  the  Barker  mill. 
Steam  is  so  light  that  for  its  utmost  utilization  as  a  jet  a  velocity 


STEAM  TURBINES 


453 


of  about  2,000  feet  a  second  is  required,  a  rate  which  no  material 
is  strong  enough  to  allow.  De  Laval  by  using  the  most  tenacious 
metals  for  his  turbines  is  able  to  give  their  swiftest  parts  a  speed 
of  as  much  as  1400  feet  a  second.  His  apparatus  is  cheap,  simple 
and  efficient ;  it  is  limited  to  about  300  horse-power.  Its  chief  fea- 
ture is  its  divergent  nozzle,  which  permits  the  outflowing  steam  to 


A,  De  Laval  nozzle  and  valve  in  section.    B,  Turbine  buckets. 
C,  Turbine  wheel. 

expand  fully  with  all  the  effect  realized  in  a  steam  cylinder  pro- 
vided with  expansion  valve  gear.  Another  device  of  De  Laval 
which  makes  his  turbine  a  safe  and  desirable  prime  mover  is  the 
flexible  shaft  which  has  a  little,  self-righting  play  under  the  ex- 
treme pace  of  its  rotation. 

Of  direct  action  turbines  the  De  Laval  is  the  chief;  of  com- 
pound turbines,  in  which  the  steam  is  expanded  in  successive 
stages,  the  first  and  most  widely  adopted  was 
invented  by  the  Hon.  Charles  A.  Parsons  of         The  Parsons 
Newcastle-on-Tyne.     From  an  address  of  his      Steam  Turbine, 
to  the  Institute  of  Electrical  Engineers,  early 
in  1905,  the  following  narrative  has  been  taken : — 


454  MOTIVE  POWERS 

"In  the  early  days  of  electric  lighting  the  speed  of  dynamos  was 
far  above  that  of  the  engines  which  drove  them,  and  therefore 
belts  and  other  forms  of  gearing  had  to  be  resorted  to.  To  make 
a  high-speed  engine,  therefore,  was  of  considerable  importance, 
and  this  led  to  the  possibilities  of  the  steam  turbine  being  con- 
sidered. It  was  at  once  seen  that  the  speed  of  any  single  turbine 
wheel  driven  by  steam  would  be  excessive  without  gearing,  and 
in  order  to  obtain  direct  driving  it  was  necessary  to  adopt  the 
compound  form,  in  which  there  were  a  number  of  turbines  in 
series,  and  thus,  the  steam  being  expanded  by  small  increments, 
the  velocity  of  rotation  was  reduced  to  moderate  limits.  Even 
then,  for  the  small  sizes  of  the  dynamos  at  that  time  in  use,  the 
speed  was  high,  and  therefore  a  special  dynamo  had  to  be  de- 
signed. Speaking  generally,  an  increase  of  speed  of  a  dynamo 
increases  its  output,  and  therefore  it  was  obvious  that  such  a  high- 
speed dynamo  would  be  very  economical  of  material. 

"These  considerations  led,  in  1884,  to  the  first  compound  steam 
turbine  being  constructed.  It  was  of  about  10  horse-power  and 
ran  at  300  revolutions  per  second,  the  diameter  of  the  armature 
being  about  three  inches.  This  machine,  which  worked  satis- 
factorily for  some  years,  is  now  in  the  South  Kensington  Museum. 
Turbines  afterward  constructed  had  two  groups  of  15  successive 
turbine  wheels,  or  rows  of  blades,  on  one  drum  or  shaft  within  a 
concentric  case  on  the  right  and  left  of  the  steam  inlet,  the  moving 
blades  or  vanes  being  in  circumferential  rows  projecting  out- 
wardly from  the  shaft  and  nearly  touching  the  case,  and  the  fixed 
or  guide  blades  being  similarly  formed  and  projecting  inwardly 
from  the  case  and  nearly  touching  the  shaft.  A  series  of  turbine 
wheels  on  one  shaft  were  thus  constituted,  and  each  one  complete 
in  itself  is  like  a  parallel-flow  water  turbine,  the  steam,  after  per- 
forming its  work  in  each  turbine,  passing  on  to  the  next,  and 
preserving  its  longitudinal  velocity  without  shock,  gradually  fall- 
ing in  pressure  as  it  passes  through  each  row  of  blades,  and 
gradually  expanding.  Each  successive  row  of  blades  was  slightly 
larger  in  passage  way  than  the  preceding  to  allow  for  the  in- 
creasing bulk  of  the  elastic  steam,  and  thus  the  velocity  of  flow 
was  regulated  so  as  to  operate  with  the  greatest  degree  of  effi- 
ciency on  each  turbine  of  the  series.  .  ,  .  It  constituted  an  ideal 


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STEAM  TURBINES  ABOARD  SHIP    455 

rotary  engine,  but  it  had  limitations.  The  comparatively  high 
speed  of  rotation  necessary  for  so  small  an  engine,  made  it  difficult 
to  avoid  a  whipping  or  springing  of  the  shaft,  so  that  considerable 
clearances  were  found  obligatory,  and  leakage  and  loss  of  effi- 
ciency resulted.  It  was  perceived  that  these  defects  would  de- 
crease as  the  engine  was  enlarged,  with  a  corresponding  reduction 
of  velocity.  In  1888  therefore  several  turbo-alternators  were  built 
for  electric  lighting  stations,  all  of  the  parallel-flow  type  and  non- 
condensing.  In  1894  the  machines  were  much  improved,  the 
blade  was  bettered  in  its  form,  and  throughout  greater  mechanical 
strength  was  attained.  .  .  .  To-day  (1905)  under  140  pounds 
steam  pressure,  100°  Fahr.  superheat,  and  a  vacuum  of  27  inches, 
the  barometer  being  at  30  inches,  the  consumptions  are  in  round 
numbers  as  follows :— A  loo-kilowatt  (134  horse-power)  plant 
takes  about  25  pounds  of  steam  per  kilowatt-hour  at  full  load,  a 
200-kilowatt  (268  horse-power)  takes  22  pounds,  a  5OO-kilowatt 
(670  horse-power)  takes  19  pounds,  a  i,5oo-kilowatt  (2,010  horse- 
power) 1 8  pounds,  and  a  3,ooo-kilowatt  (4,020  horse-power)  16 
pounds  (or  12  pounds  per  horse-power-hour).  Without  super- 
heat the  consumptions  are  about  10  per  cent,  more,  and  every  10° 
Fahr.  of  superheat  up  to  about  150°  lowers  the  consumption  about 
i  per  cent. 

"A  good  vacuum  is  of  great  importance  in  a  turbine,  as  the  ex- 
pansion can  be  carried  in  the  turbine  right  down  to  the  vacuum 
of  the  condenser,  a  function  which  is  practically  impossible  in  the 
case  of  a  reciprocating  engine,  on  account  of  the  excessive  size 
of  the  low-pressure  cylinder,  ports,  passages  and  valves  which 
would  be  required.  Every  inch  of  vacuum  between  23  and  28 
inches  lowers  the  consumption  about  3  per  cent,  in  a  loo-kilowatt, 
4  per  cent,  in  a  5OO-kilowatt,  and  5  per  cent,  in  a  i,5OO-kilowatt 
turbine,  the  effect  being  more  at  high  vacua  and  less  at  low." 

In  1894  Mr.  Parsons  launched  his  "Turbinia,"  the  first  steamer 
to  be  driven  by  a  turbine.     Her  record  was  so  gratifying  that  a 
succession  of  vessels,  similarly  equipped,  were 
year  by  year  built  for  excursion  lines,  for  transit       Marine  Steam 
across   the    British    Channel,    for   the    British  Turbines. 

Royal  Navy,  and  for  mercantile  marine  service. 
The  thirty-fifth  of  these  ships,  the  "Victorian"  of  the  Allan  Line, 


456  MOTIVE  POWERS 

was  the  first  to  cross  the  Atlantic  Ocean,  arriving  at  Halifax,  Nova 
Scotia,  April  18,  1905.  She  was  followed  by  the  " Virginian"  of 
the  same  line  which  arrived  at  Quebec,  May  8,  1905.  Not  long 
afterward  the  Cunard  Company  sent  from  Liverpool  to  New 
York  the  "Carmania"  equipped  with  steam  turbines,  and  in  every 
other  respect  like  the  "Caronia"  of  the  same  owners,  which  is 
driven  by  reciprocating  engines  of  the  best  model.  Thus  far  the 
comparison  between  these  two  ships  is  in  favor  of  the  "Car- 
mania."  The  new  monster  Cunarders,  the  "Lusitania"  and  the 
"Mauretania,"  each  of  70,000  horse-power,  are  to  be  propelled  by 
steam  turbines.  The  principal  reasons  for  this  preference  are  thus 
given  by  Professor  Carl  C.  Thomas  :— 

Decreased  cost  of  operation  as  regards  fuel,  labor,  oil,  and 
repairs. 

Vibration  due  to  machinery  is  avoided. 

Less  weight  of  machinery  and  coal  to  be  carried,  resulting  in 
greater  speed. 

Greater  simplicity  of  machinery  in  construction  and  operation, 
causing  less  liability  to  accident  and  breakdown. 

Smaller  and  more  deeply  immersed  propellers,  decreasing  the 
tendency  of  the  machinery  to  race  in  rough  weather. 

Lower  centre  of  gravity  of  the  machinery  as  a  whole,  and  in- 
creased headroom  above  the  machinery. 

According  to  recent  reports,  decreased  first  cost  of  machinery.1 

1  "Steam  Turbines,"  by  Carl  C.  Thomas,  professor  of  marine  engineering, 
Cornell  University,  a  comprehensive  and  authoritative  work,  fully  illus- 
trated. New  York,  John  Wiley  &  Sons,  1906.  $3.50. 


CHAPTER  XXXI 

MOTIVE  POWERS  PRODUCED  WITH  NEW  ECONOMY— 
Continued.    HEATING  SERVICES 

Producer  gas  .  .  .  Mond  gas  .  .  .  Blast  furnace  gases  .  .  .  Gas  engines 
.  .  .  Steam  and  gas  engines  compared  .  .  .  Diesel  oil  engine  best  of 
all  ...  Gasoline  motors  .  .  .  Alcohol  engines  .  .  .  Steam  and  gas 
motors  united  .  .  .  Heat  and  power  production  combined  .  .  .  District 
steam  heating  .  .  .  Isolated  plants  .  .  .  Electric  traction  and  other  great 
services  .  .  .  Gas  for  a  service  of  heat,  light  and  power. 

STEAM  as  motive  power  finds  its  most  -formidable  rival  in 
cheap  gases,  whose  familiar  varieties  have  been  long  used 
for  illumination.  A  simple  experiment  shows  with  what  ease  gas 
can  be  made,  which,  duly  cooled,  may  be  carried  long  distances 
without  the  condensation  which  subtracts  from 
the  value  of  steam.  Take  a  narrow  tube  of  Gas-Power. 
metal  or  Jena  glass,  open  at  both  ends :  put  one 
end  near  the  wick  of  a  burning  candle,  at  the  other  end  apply  a 
lighted  match,  and  at  once  a  flame  bursts  forth.  Here  is  a 
miniature  gas-works ;  close  to  the  wick  inflammable  gases  are  gen- 
erated by  the  heat,  before  they  have  time  to  burn  they  are  con- 
veyed through  the  tube  to  a  point  a  foot  distant  where,  on  ignition, 
they  yield  a  brilliant  flame.  Enlarge  this  operation  so  that  instead 
of  an  ounce  of  wax  you  distill  tons  of  coal  from  hundreds  of  big 
retorts ;  set  up  a  gas-holder  as  huge  as  the  dome  of  the  Capitol  at 
Washington ;  instead  of  short  tube  lay  miles  of  pipe  through  the 
avenues  and  streets  of  a  city,  and  a  trivial  experiment  widens  into 
lighting  a  hundred  thousand  homes.  So  much  for  dividing  com- 
bustion in  halves,  by  conducting  gasification  in  one  place  on  a  vast 
scale,  and  burning  the  produced  gas  whenever  and  wherever  you 
please.  One  supreme  advantage  of  the  process  is  that  coal,  wood 
and  other  sources  of  gas  much  cheaper  than  wax  or  oil  can  be 

457 


458 


MOTIVE  POWERS 


employed.  Alongside  the  retorts  which  gasify  coal  or  wood  are 
built  scrubbers  which  remove  substances  undesired  in  the  gas,— 
tar,  sulphur,  and  so  on,— all  salable  at  good  prices.  It  was  in  1792 
that  William  Murdock,  an  assistant  to  Tames  Watt  at  the  Soho 
Works  near  Birmingham,  there  originated  gas-lighting.  His 

enterprise  was  a  seed-plot  for 
A  a  variety  of  industries  which 
®  have  reached  commanding 
importance,  and  are  to-day 
expanding  faster  than  evei 
before.  Illuminating  gas 
from  its  first  introduction  has 
on  occasion  wrought  dis- 
aster ;  when  it  leaks  through 
a  joint  into  a  room  it  rapidly 
unites  with  air;  instantly  on 
the  intrusion  of  a  flame  there 
is  a  violent  explosion,  that  is, 
an  abrupt  output  of  enormous 
energy  set  free  under  circum- 
stances which  do  only  harm. 
Can  the  energy,  as  in  the  case 
of  blasting,  be  usefully  di- 
rected ? 

Yes,  as  long  ago  as  1794,  Robert  Street  designed  a  pump  driven 
by  the  explosion  of  turpentine  vapor  below  the  motor  piston.  He 
was  followed  by  inventors  who  used  illuminating  gas  as  their 
propelling  agent;  among  these,  in  1860,  was  Lenoir  of  Paris,  who 
built  a  double-acting  engine  with  a  jump-spark  electric  igniter 
such  as  to-day  is  in  general  use.  His  engine  consumed  95  feet  of 
gas  per  hour  for  each  horse-power,  which  meant  that  commercially 
the  engine  was  a  failure.  Lenoir's  design  has  been  so  much  im- 
proved that  now  large  gas  engines  yield  in  motive  power  one  fifth 
of  the  whole  value  of  their  fuel,  an  efficiency  twice  that  cf  the  best 
steam  engines  or  turbines,  and  five-fold  better  than  that  of 
Lenoir's  apparatus. 

How  this  remarkable  result  has  been  attained  we  shall  consider 
a  little  further  on,  as  we  briefly  examine  the  construction  of  a 


Combustible  gas  from  a  candle  is  taken 
through  a  tube  to  a  distance  and 
there  burnt. 


PRODUCER  GAS  459 

typical  gas  engine.  At  this  point  let  us  note  how  a  gas,  suitable 
for  an  engine,  is  manufactured  at  least  cost,  the  outlay  being 
much  less  than  in  the  case  or  illuminating  gas  which  represents 
but  one  third  of  the  coal  placed  in  the  distilling  retorts.  Instead 
of  this  process  of  distillation,  "producer"  gas 
is  due  to  a  modified  combustion  which  gasifies  Producer  Gas. 
all  the  fuel.  In  a  producer  of  standard  type, 
atmospheric  oxygen  comes  into  contact  with  the  glowing  carbon  of 
the  coal  or  wood,  forming  carbon  dioxide,  CO".  The  lieat  gen- 
erated by  this  union  is  taken  up  by  the  carbon  dioxide  and  the 
nitrogen  of  the  supplied  air.  These  gases  as  they  rise  through  the 
fuel  bring  it  to  incandescence  so  that  the  carbon  dioxide  takes  up 
another  atom  of  carbon,  becoming  carbon  monoxide,  CO,  a  highly 
combustible  gas.  Were  there  no  impurities  in  the  fuel,  were  the 
entering  air  quite  free  from  moisture,  the  gases  would  be  in  vol- 
ume 34.7  per  cent,  carbon  monoxide  and  65.3  per  cent,  nitrogen, 
with  a  heating  value  per  cubic  foot  of  about  118  British  thermal 
units,  a  unit  being  the  heat  needed  to  raise  a  pound  of  water  to 
40°  Fahr.  from  39°,  where  its  density  is  at  the  maximum.  Gas 
thus  produced  is  intensely  hot ;  and  as  usually  it  contains  sulphur, 
dust,  dirt,  and  other  admixtures,  their  removal  by  water  in  a 
scrubber  would  involve  a  waste  of  about  30  per  cent,  of  the  fuel 
heat.  This  loss  is  much  diminished  by  sending  into  the  producer 
not  only  air  but  steam,  to  be  decomposed  into  oxygen  and  hy- 
drogen ;  the  oxygen  combines  with  carbon  to  form  more  carbon 
monoxide,  while  the  hydrogen  is  the  most  valuable  heating  in- 
gredient in  the  emitted  stream  of  gases.  Were  only  air  sent 
through  the  producer,  the  outflowing  gases  would  contain  nitrogen 
to  the  extent  of  65  per  cent. ;  with  a  charge  in  part  air  and  in  part 
steam,  this  percentage  falls  to  52 ;  as  nitrogen  is  useless  and  waste- 
fully  absorbs  heat,  this  reduction  of  its  quantity  is  gainful.  By  a 
duly  regulated  admission  of  steam,  a  producer  is  kept  at  a  tem- 
perature high  enough  to  decompose  steam,  but  not  so  high  as  to 
send  forth  gases  unduly  hot  to  the  purifier. 

For  water-gas  the  method  is  to  blow  steam  into  the  fuel  until 
decomposition  ceases ;  the  steam  is  then  shut  off,  the  fire  allowed 
to  recover  intense  heat,  when  more  steam  is  injected,  and  so  on 
intermittently. 


460 


MOTIVE  POWERS 


Producer  gas  is  in  more  extensive  use  than  water-gas.     It  is 

evolved  in  apparatus  of  many  gc  >d  designs :  let  us  glance  at  the 

Taylor  gas  producer  built  by  R.  D.  Wood  & 

A  Gas  Producer.      Company,   Philadelphia.     Its   fuel  enters  in  a 

steady  stream,  in  controlled  quantity,  through 

a  Bildt  automatic  feed  which  has  a  constantly  rotating  distributor 

with  deflecting  surfaces.     The  incandescent  fuel  is  carried  on  a 

bed  of  ashes  several  feet  thick,  so 
that  the  coal  gradually  burns  out 
and  cools  before  its  ashes  are  dis- 
charged. Through  a  conduit  an 
airblast  is  carried  up  through 
this  layer  of  ashes  to  where  the 
fuel  is  aglow;  united  with  this 
airblast  is  a  pipe  admitting  steam ; 
the  united  air  and  steam  are 
emitted  radially.  In  the  producer 
walls  are  sight  or  test  holes  so 
placed  that  the  line  dividing  ashes 
from  glowing  fuel  may  at  any 
time  be  observed.  When  this  line 
becomes  higher  on  one  side  than 
the  other,  scrapers,  duly  arranged, 
are  used.  At  the  bottom  of  the 
producer  is  a  Taylor  rotative 
table  which  grinds  out  the  ashes 
as  fast  as  they  rise  above  the  de- 
sired depth,  say  every  six  to 
twenty-four  hours,  according  to 
the  rate  of  working.  In  large  pro- 
ducers the  ash  bed  is  kept  about 
three  and  a  half  feet  deep,  so  that 

any  coal  that  may  pass  the  point  of  air  admission  has  ample  time 
to  burn  entirely  out:  in  a  producer  with  an  ordinary  grate  such 
coal  would  fall  wastefully  into  the  ashpit.  As  the  Taylor  ash 
table  turns  it  grinds  the  lower  part  of  the  fuel  bed,  closing  any 
channels  formed  by  the  airblast,  and  restraining  the  formation  of 
carbon  dioxide,  a  useless  product,  to  a  minimum.  A  few  impulses 


Taylor  gas-producer. 
R.  D.  Wood  &  Co.,  Philadelphia. 


MOXD  GAS  461 

of  the  crank  at  frequent  intervals  maintain  the  fuel  in  solid  con- 
dition, reducing  the  need  of  poking  from  above. 

Other  American  producers  differ  from  the  Wood  apparatus  in 
details  of  design  and  operation;  in  principle  all  are  much  alike. 
Any  good  producer  works  well  with  cheap  fuels,  bituminous  coals 
of  inferior  quality,  culm,  lignite,  wood,  peat,  tanbark,  and  even 
straw  from  the  thresher.  With  each  of  these  there  must  be  due 
modification  of  mechanism,  together  with  means  of  forcing  air 
and  steam  into  the  fire.  A  suction  plant  may  be  employed  when 
superior  fuels  are  burned,  coke,  anthracite,  or  charcoal ;  with  cur- 
rents of  air  and  steam  automatically  drawn  into  the  producer, 
the  surrounding  room  is  not  likely  to  be  filled  with  the  harmful- 
gases  which  may  be  occasionally  ejected  by  a  pressure  plant. 

England  has  gas-power  installations  much  larger  and  more 
elaborate  than  those  of  America.  Of  these  the  most  extensive 
have  been  built  by  the  Power-gas  Corporation 
in  London,  under  the  patents  of  Mond,  Duff  Mond  Gas. 
and  Talbot.  A  Mond  plant  yields  a  gas  having 
84  per  cent,  of  the  calorific  value  of  the  coal  consumed,  which  may 
be  slack  at  six  shillings,  $1.46,  per  ton.  Where  more  than  thirty 
tons  of  coal  per  day  are  used,  it  is  worth  while  intercepting  the 
sulphate  of  ammonia,  amounting  to  90  pounds  per  ton  of  coal, 
which  in  small  producers  cannot  readily  be  seized.  Mond  gas 
is  free  from  tar,  is  cleansed  of  soot  and  dust,  and  holds  less  sul- 
phur than  ordinary  producer  gas.  Operation  is  simple  enough : 
first  of  all  the  slack  is  brought  into  hoppers  above  the  producers. 
From  these  it  is  fed  in  charges,  of  from  300  to  1,000  pounds,  into 
the  producer  bell,  where  the  first  heating  takes  place :  the  products 
of  distillation  pass  downward  into  the  hot  zone  of  fuel  before 
joining  the  bulk  of  gas  leaving  the  producer.  This  converts  the 
tar  into  a  fixed  gas,  and  prepares  the  slack  for  descent  into  the 
body  of  the  producer,  where  it  is  acted  upon  by  an  airblast  satu- 
rated with  steam  at  185°  Fahr.,  and  superheated  before  coming 
into  contact  with  the  fuel.  The  stream  of  hot  gases  from  the 
producer  now  traverses  a  washer,  a  rectangular  iron  chamber  with 
side  lutes,  where  a  water  spray  thrown  by  revolving  dashers  brings 
down  the  temperature  of  the  gases  to  about  194°  Fahr.  In  plants 
which  recover  the  ammonia  sulphate,  the  gas  takes  its  way  through 


462  MOTIVE  POWERS 

a  lead-lmed  tower,  filled  with  tiles  of  large  surface,  where  it  meets 
a  downward  flow  of  acid  liquor,  circulated  by  pumps,  containing 
ammonia  sulphate  with  about  4  per  cent,  excess  of  free  sulphuric 
acid.  Combination  of  the  ammonia  with  this  free  acid  ensues, 
yielding  still  more  ammonia  sulphate.  The  gases,  freed  from 
their  ammonia,  are  conducted  into  a  cooling  tower,  where  they 
meet  a  descending  shower  of  cold  water  effecting  a  further 
cleansing  before  the  gases  enter  the  main  pipe  for  delivery  to  con- 
sumers. In  its  general  plan,  a  Mond  plant  resembles  an  illumi- 
nating gas  works,  especially  in  its  seizure  of  profitable  by-pro- 
ducts. A  ton  of  slack  costing  in  England  $1.46  yields  90  pounds 
of  ammonia  sulphate  worth  $1.92  or  thereabout.1 

For  many  years  flames  from  blast  furnaces  and  coke  ovens  testi- 
fied to  the  waste  of  valuable  gases,  in  especial  the  combustible  car- 
bon monoxide  which  is  the  main  ingredient  in 
Blast  Furnace  producer  gas.  When  we  learn  that  coal  or  coke 
in  iron-smelting  parts  with  but  three  per  cent, 
of  its  heat  to  the  ore,  we  begin  to  see  how  grievous  was  the  waste 
so  long  endured.  For  a  few  years  past  the  gases  sent  forth  from 
blast  furnaces  have  been  employed  to  heat  the  incoming  air  for 
the  blowers,  and  to  raise  steam  for  engines.  With  twice  the  effi- 
ciency of  steam  motors  the  gas  engine  renders  it  well  worth  while 
to  rid  furnace  gases  of  their  dust  and  dirt  so  that  they  may  not 
injure  the  mechanism  they  impel.  An  effective  cleanser  acts  by 
separating  the  gases  from  their  admixtures  by  centrifugal  force. 
At  the  Lackawanna  Steel  Works,  Buffalo,  N.  Y.,  eight  gas-en- 
gines, each  of  1,000  horse-power,  are  run  on  blast  furnace  gases. 
It  may  well  prove  that  installations  of  this  kind  will  bring  other 
blast  furnaces  into  cities  where  the  sale  of  electricity  will  form  a 
large  item  in  the  profits. 

The  first  gas  engines  used  gas  and  air  at  ordinary  atmospheric 

pressure;  at  due  intervals  the  charge  was  exploded  by  a  glowing 

hot  tube  exposed  by  a  slide-valve,  or,  according 

Gas  Engines.        to  the  practice  now  general,  by  an  electric  spark 

of   the    jump   variety.      In    1862    De   Rochas 

1  "Producer-gas  and  Gas-producers,"  by  Samuel  S.  Wyer,  is  a  treatise 
of  value,  fully  illustrated.  New  York,  Engineering  and  Mining  Journal, 
1906.  $4.00. 


GAS  ENGINES 


463 


patented,  and  in  1876  Otto  built,  an  engine  on  a  model  still  in 
favor.  Its  cardinal  feature  is  the  compression  of  each  charge. 
In  the  field  of  steam  practice,  we  know  how  great  economy  is  real- 
ized by  beginning  work  with  high  pressures.  A  similar  gain  at- 


Four-cycle  gas  engine.    I,  admission  valve. 
O,  exhaust  valve. 

tends  the  compression  of  gases  in  a  cylinder  before  explosion; 
whatever  their  pressure  before  ignition,  it  is  trebled  or  quadrupled 
by  ignition,  returning  a  handsome  profit  on  the  work  of  compres- 
sion. The  four-cycle  operation  devised  by  De  Rochas  proceeds 
thus :— First,  by  drawing  in  a  mixture  of  gas  and  air  in  due  per- 
centages during  an  outward  stroke  of  the  piston.  Second,  this 
charge  is  compressed  by  an  inward  piston  stroke.  Third,  the  com- 
pression charge  is  ignited,  preferably  by  an  electric  spark,  when 


464  MOTIVE  POWERS 

the  piston  moves  outward  by  virtue  of  a  pressure  initially  ex- 
treme. Fourth,  the  exhaust  valve  opens  and  the  spent  gases  are 
ejected  as  the  piston  returns  to  complete  its  cycle.  As  but  one  of 
the  four  piston  journeys  is  a  working  stroke,  it  is  necessary  to 
employ  a  heavy  flywheel  to  equalize  the  motion  of  the  engine. 
When  two  or  more  engines  are  united,  their  piston  rods  are  so 
connected  to  a  common  shaft  as  to  distribute  the  working  strokes 
with  the  best  balancing  effect.  With  four  engines  their  piston 
rods  may  be  arranged  at  distances  apart  of  90  degrees,  so  that  one 
working  stroke  is  always  being  exerted.  This  plan  is  adopted  for 
the  gasoline  engines  of  automobiles  so  that  they  are  served  by 
fly-wheels  comparatively  small. 

In  his  work  on  the  gas  engine,  Professor  F.  R.  Hutton  dis- 
cusses the  advantages  and  disadvantages  of  that  motor.1  By  his 
kind  permission  his  main  conclusions  may  be  thus  summarized, 
first  as  to  advantages  : — 

The  heat  energy  acts  directly  upon  the  piston,  without  inter- 
vening appliances.  Fuel  economy  is  greater  than  with  steam,  be- 
cause there  is  no  furnace  or  chimney  to  waste  any  heat.  No  fuel 
is  wasted  in  starting  the  motor,  or  after  the  engine  stops.  The 
bulk,  weight  and  cost  of  a  furnace  and  boiler  are  eliminated,  as 
well  as  their  losses  by  radiation.  A  gas  motor  has  a  portability 
which  lends  itself  to  important  industries,  as  logging  and  lumber- 
ing. It  may  be  started  at  once,  with  no  delay  as  in  getting  up  a 
fire  under  a  boiler ;  when  the  fuel-supply  is  cut  off,  the  motor 
stops  and  needs  no  attention :  these  are  important  in  automobile 
practice.  Gas  engines  are  gainfully  united  to  systems  of  gas 
storage  so  that  a  producer  may  be  run  at  high  efficiency  when  con- 
venient, and  its  gas  held  in  holders  till  needed :  this  is  helpful 
when  a  plant  is  worked  overtime,  or  is  liable  to  stresses  of  ex- 
treme demand  at  certain  hours  of  the  day.  Incident  to  this  is  the 
advantage  of  subdividing  power  units  in  a  large  plant :  each  motor 
may  receive  its  gas  in  pipes  without  loss,  to  be  operated  at  will. 
The  rapidity  of  flame  propagation  renders  possible  a  high  num- 

1  "The  Gas-engine :  a  treatise  on  the  internal-combustion  engine  using 
gas,  gasoline,  kerosene,  or  other  hydro-carbon  as  source  of  energy."  By 
F.  R.  Hutton,  professor  of  mechanical  engineering  in  Columbia  University. 
New  York,  John  Wiley  &  Sons.  $5.00. 


GAS  ENGINES  465 

her  of  shaft  rotations  per  minute,  so  that  a  multi-cylinder  engine 
weighs  little  in  comparison  with  its  power.  There  is  no  liability 
to  boiler  explosion,  or  trouble  from  impurities  deposited  by  water 
in  a  boiler.  There  is  no  exposed  flame  or  fuel-bed  requiring  at- 
tention. The  mechanism  of  the  motor  is  simple,  and  its  moving 
parts  are  few.  A  gas  or  oil  engine  furthermore  enjoys  a  com- 
bustion which  is  smokeless.  The  fuel  requires  no  diluting  excess 
of  air,  with  its  cooling  effect  and  incidental  waste  of  energy. 
Dust,  sparks  and  ashes  are  avoided,  with  diminished  risk  of  fire. 
Liquid  or  gaseous  fuel  can  be  served  by  pumps  or  blowers  so  that 
the  cost  of  handling  is  avoided. 

As  to  disadvantages :— In  a  four-cycle  engine  there  is  but  one 
working  stroke  in  four  piston  traverses.  In  a  two-cycle  engine 
there  is  one  working  stroke  in  two  traverses.  For  a  given  mean 
pressure  the  cylinder  of  a  gas  engine  must  be  larger  than  a  double 
acting  steam  cylinder.  In  single  cylinder  gas  engines  the  crank 
effort  is  irregular ;  hence  a  heavy  fly-wheel  is  required,  or,  a  num- 
ber of  cylinders  must  be  joined  together,  adding  mi;ch  weight. 
The  motor  does  not  start  by  the  simple  motion  of  a  lever  or  valve. 
It  has  to  be  started  by  an  auxiliary  apparatus  stored  with  energy 
enough  to  cause  one  working  stroke.  A  steam  engine  may  be 
overloaded  to  meet  brief  demands  for  extra  power:  not  so  with 
a  gas  engine.  The  extreme  temperatures  of  the  cylinder  require 
cooling  systems  by  air  or  water,  adding  weight  and  involving 
waste  of  energy;  these  temperatures  furthermore  may  seriously 
distort  the  mechanism  while  rendering  lubrication  difficult  and 
uncertain.  Explosions  of  some  violence  may  occur  in  exhaust  pipes 
and  passages,  unless  the  engine  is  carefully  adjusted  and  oper- 
ated. Imperfect  combustion  clogs  the  working  parts  with  soot  or 
lampblack,  especially  injuring  the  ignition  appliances.  Initial 
pressures  are  so  high  as  to  cause  vibration  and  jar.  Governing  is 
not  easy,  since  explosion  is  all  but  instantaneous.  The  normal 
motor  runs  at  maximum  efficiency  only  when  running  at  a  certain 
speed.  To  vary  that  speed  is  much  more  troublesome  and  waste- 
ful of  energy  than  with  the  steam  engine. 

Gas  engines  united  to  gas  producers  have  been  employed  with 
success  on  shipboard.  This  field,  with  its  high  premium  on  fuel 
reduction,  which  means  more  space  for  cargo,  is  likely  to  be 


466  MOTIVE  POWERS 

largely  developed  in  the  near  future.    Soon,  also,  we  may  expect 
locomotives  to  exhibit  a  like  combination  with  profitable  results. 
During  1904  and  1905  the  U.  S.  Geological  Survey  compared 
at  St.  Louis  a  steam  engine  with  a  gas  engine,  each  of  250  horse- 
power, using  24  varieties  of  lignites  and  bitu- 
Steam  and  Gas       minous   coals.      The    steam   engine    was   of    a 

Engines  ,  ,        .  ,          ,       ~     ,. 

Compared  simple,     non-condensing,     unjacketed     Corliss 

type,  from  the  Allis-Chalmers  Company,  Mil- 
waukee. The  gas  engine  was  a  three-cylinder,  vertical  model 
from  the  Westinghouse  Machine  Company,  Pittsburg.  Its  gas 
was  supplied  by  a  Taylor  gas  producer  furnished  by  R.  D.  Wood 
&  Company,  Philadelphia,  of  the  design  illustrated  on  page  460. 
The  official  report  in  three  parts,  fully  illustrated,  presenting 
the  tests  in  detail,  was  published  by  the  Survey  early  in  1906.  On 
page  978,  of  the  second  part,  14  comparative  tests  are  summarized. 
They  show  that  in  the  gas  plant  on  an  average  1.70  pounds  of  fuel 
were  consumed  in  producing  for  one  hour  one  electrical  horse- 
power;'^! the  steam  plant  the  consumption  was  4.29  pounds,  two 
and  a  half  times  as  much.  With  apparatus  adapted  to  a  particular 
fuel,  with  larger  and  more  economical  engines,  better  results 
would  have  been  shown  both  by  steam  and  gas.  Yet  competent 
critics  believe  that  the  ratio  of  net  results  would  have  remained 
much  the  same.  The  most  important  fact  brought  out  in  the 
tests  is  that  some  fuels,  lignites  from  North  Dakota  for  example, 
have  little  worth  in  raising  steam,  and  high  value  in  producing 
gas ;  their  moisture  is  a  detriment  under  a  boiler,  it  is  an  advantage 
in  a  gas  producer.  The  cost  of  this  investigation  is  likely  to  be 
repaid  many  thousand-fold  in  pointing  out  the  best  way  to  use 
fuels  which  abound  in  the  Western  and  Northwestern"  States  and 
in  Canada.  See  note,  page  241. 

In  some  cases  petroleum  is  the  best  available  fuel  for  an  engine , 
essentially  much  the  same  as  a  gas  motor.    A  carburetor,  or  atom- 
izer, blows  the  oil  into  a  fine  mist  almost  as  in- 
Oil  Engines.         flammable  as  gas.    In  small  sizes  for  launches, 
threshing  machines,  or  work-shops  of  limited 
area,  the  petroleum  engine  is  a  capital  servant.     In  sizes  of  75 
horse-power  and  upward  the  Diesel  engine  is  not  only  the  best  oil 
engine  but  the  most  efficient  heat-motor  ever  invented.  It  involves 


THE  BEST  HEAT  ENGINE  467 

a  principle  as  important  as  that  of  Watt's  separate  condenser  for 
the  steam  from  his  cylinder. 

To  understand  the  Diesel  principle  let  us  begin  by  remembering 
that  to  the  compression  of  a  charge  in  a  gas  engine  there  is  a 
moderate  limit;  if  this  be  exceeded  the  heat  of  compression 
prematurely  ignites  the  gases,  so  as  to  prevent  due  action.  The 
air  in  a  bicycle  tire  is  compressed  but  moderately,  and  yet  every 
man  who  has  worked  a  bicycle  air-pump  with  energy  knows  that 
soon  its  cylinder  grows  warm  to  the  touch.  On  this  very  prin- 
ciple, that  mechanical  work  is  convertible  into  heat,  our  grand- 
fathers had  an  ingenious  mode  of  producing  fire.  In  a  syringe 
with  a  glass  barrel  they  placed  a  piston  fitting  snugly.  In  a  cavity 
of  this  piston  they  fastened  a  bit  of  cotton  wool  soaked  in  bisul- 
phide of  carbon.  On  forcing  the  piston  suddenly  into  the  cylinder, 


Fire  Syringe. 


the  air,  quickly  compressed,  became  hot  enough  to  set  the  cotton 
wool  on  fire.  The  heat  evolved  in  the  compression  of  air  is  turned 
to  account  in  the  Diesel  oil  -engine  so  as  to  make  it  the  most  eco- 
nomical converter  of  heat  into  work  ever  devised.  First  the  me- 
chanism compresses  air  alone  to  500  pounds  per  square  inch,  then 
and  then  only  the  oil  for  combustion  is  injected,  to  take  fire  in- 
stantly from  the  heat  of  the  compressed  air.  A  governor  regu- 
lates the  period  of  burning;  this  is  usually  during  one  tenth  part 
of  the  stroke,  the  expansion  of  the  burned  products  completing 
the  stroke.  Because  500  pounds  is  a  pressure  out  of  the  question 
for  the  compression  of  the  mixed  charge  of  air  and  combustible 
gas  in  an  ordinary  gas  cylinder,  the  Diesel  engine  excels  in  econ- 
omy any  gas  engine  thus  far  built.  At  Ghent  in  1903  a  Diesel  en- 
gine developed  165  brake  horse-power  from  crude  Texas  oil  with 
the  extraordinary  net  efficiency  of  32.3  per  cent.  At  the  St.  Louis 


468  MOTIVE  POWERS 

Exposition,  1904,  three  Diesel  engines,  using  oil  costing  three 
cents  per  gallon,  delivered  for  seven  months,  during  eleven  hours 
each  day,  at  half-load,  an  average  of  250  kilowatts  at  an  expense 
for  fuel  of  but  three  tenths  of  one  cent  per  kilowatt  hour  on 
the  switchboard,  including  all  generator  and  line  losses.  En- 
gineers of  the  first  rank  are  convinced  that  the  Diesel  principle 
may  be  successfully  ^^nbodied  in  gas  engines.  That  done,  with  a 
success  approaching  the  effectiveness  of  Diesel's  oil  motor,  we 
may  expect  steam  engines  and  turbines  to  be  largely  dismissed 
from  service. 

Gasoline,  although  higher  in  price  than  petroleum,  is  commonly 
used  in  automobiles  and  launches.     It  can  be  atomized  more 

quickly  and  fully,  and  without  heat.  To  equal- 
Gasoline  Engines,  ize  motion,  minimize  jars,  and  reduce  the 

weight  of  its  fly-wheel,  an  automobile  of  high 
power  has  usually  four  cylinders  with  cranks  set  at  an  angle  of  90 
degrees  with  each  other.  The  inlet  valve  is  operated  positively 
and,  as  a  rule,  is  interchangeable  with  the  exhaust  valve.  The 
ignition  spark  is  furnished  by  a  motor-driven  magneto,  or  by  a 
battery  operating  an  induction  coil ;  the  lubricant  is  distributed  by 
a  sight-feed  system,  hand  regulated.  Cooling  is  effected  by  water 
circulated  by  a  pump  through  jackets  surrounding  all  cylinders 
and  valves,  each  jacket  having  a  surface  of  the  utmost  extent  upon 
which  a  swiftly  rotated  fan  drives  a  stream  of  air. 

For  some  years  France  and  Germany  have  used  alcohol  as  a 
fuel  in  engines,  no  excise  tax  being  imposed  on  alcohol  employed 

for  industrial  purposes.     On  January  I,  1907, 
Alcohol  Engines,     this  will  also  be  the  case  in  the  United  States,  so 

that  we  may  expect  alcohol  to  take  a  leading 
place  as  fuel  in  motors.  "It  has,"  says  Professor  Elihu  Thom- 
son, "gallon  for  gallon  less  heating  power  than  gasoline,  but  equal 
efficiency  in  an  internal  combustion  engine,  because  it  throws  away 
less  heat  in  waste  gases  and  in  the  water  jacket.  A  mixture  of 
alcohol  vapor  with  air  stands  a  much  higher  compression  than 
does  a  mixture  of  gasoline  and  air  without  premature  explosion. 
.  .  .  There  is  now  beginning  an  application  of  the  internal  com- 
bustion engine  for  railroad  cars  on  short  lines  which  are  feeders 
to  main  lines.  The  growth  of  this  business  may  be  hampered  in 


STEAM  ENGINE  LOSSES  469 

the  near  future  by  the  cost  of  gasoline.    In  this  case  alcohol,  pro- 
ducible in  unlimited  amount,  could  be  substituted." 

An  important  advantage  in  using  alcohol  is  its  comparative 
safety.  In  case  of  fire  oils  and  gasolines  float  on  the  water  in- 
tended to  quench  a  blaze ;  alcohol  blends  with  that  water  and  the 
flame  is  subdued. 

Whether  oil,  gasoline  or  alcohol  be  their  fuel,  internal  com- 
bustion motors  gain  steadily  in  public  acceptance.  On  the  farm 
they  are  gradually  displacing  the  horse.  An  engine,  which  costs 
nothing  when  it  is  idle,  shells  corn,  saws  wood,  cuts  fodder,  grinds 
feed,  separates  and  churns  cream,  drives  a  thrasher,  turns  a  mill, 
lifts  water,  and  performs  a  hundred  other  chores  quickly,  simply 
and  cheaply. 

Mr.  Henry  G.  Stott,  chief  engineer  of  the  Interborough  Rapid 
Transit  Company,  New  York,  has  recently  discussed  power  plant 
economies   in    so  thorough   and    suggestive   a 
manner  as  to  elicit  the  interest  of  engineers  the     steam  and  Gas 
world  over.1  Basing  his  remarks  on  the  records     Motors  United, 
of  the  huge  plant  of  his  Company  at  74th  Street 
and  the  East  River,  New  York,  he  presents  this  table  of  the 
average  losses  in  converting  the  heat  from  one  pound  of  coal  into 
electricity  :— 

Heat  of  the  coal  as  burned,  14,150  British  thermal  units 100.0% 

Returned  by  feed  water  heater 3.1 

"   economizer  6.8 

109.9 

Loss  in  ashes 2.4% 

Loss  to  stack 22.7 

Loss  in  boiler  radiation  and  leakage 8.O 

Loss  in  pipe  radiation 0.2 

Delivered  to  circulator 1.6 

"  feedpump  1.4 

Loss  in  leakage  and  high  pressure  drips I.I 

Delivered  to  small  auxiliaries 04 

Heating  0.2 

Loss  in  engine  friction 0.8 

*  Before  the  American  Institute  of  Electrical  Engineers,  New  York, 
January  26,  1906. 


470  MOTIVE  POWERS 

Electrical  losses  0.3 

Engine  radiation  losses  . . .  . 0.2 

Rejected  to  condenser 60.1 

To  house  auxiliaries 0.2          99.6 


Delivered  to  bus-bar  ' 10.3% 

Carbon  dioxide  (CO2)  is  absorbed  by  a  solution  of  caustic  pot- 
ash. The  Ados  recorder  based  upon  this  absorption  has  enabled 
Mr.  Stott  to  learn  the  proportion  of  carbon  dioxide  in  the  gases 
passing  to  the  stack,  the  higher  that  proportion,  the  more  thorough 
the  combustion.  He  finds  first  as  an  element  of  economy  careful 
firing,  so  as  to  avoid  "holes"  or  thin  places  in  a  fire,  through 
which  air  wastefully  pours,  chilling  J:he  furnace.  Next  in  im- 
portance is  adapting  draft  to  fuel :  small  anthracite  requires  a 
draft  of  1.5  inches  of  water;  with  a  draft  of  but  .2  inch  of  water 
one  pound  of  dry  bituminous  coal  has  evaporated  10.6  pounds  of 
water,  with  a  draft  of  I  inch  this  fell  to  8.7  pounds.  Mr.  Stott 
estimates  that  scientific  methods  of  firing  can  reduce  losses  to  the 
stack  to  12.7  per  cent.,  and  possibly  to  "•»  per  cent. 

Respecting  the  loss  of  8  per  cent,  in  boiler  radiation  and  leak- 
age, he  maintains  that  this  is  largely  due  to  the  inefficient  setting 
of  brick  which,  besides  permitting  radiation,  admits  much  air  by 
infiltration.  The  remedy  is  to  employ  the  best  methods  of  boiler 
setting,  such  as  an  iron-plate  air-tight  case  enclosing  a  carbonate 
of  magnesia  lining  outside  the  brickwork. 

Regarding  the  main  loss,  that  of  60. i  per  cent,  to  the  condenser, 
Mr.  Stott  points  out  that  superheating  could  reduce  this  by  6  per 
cent.  He  observes  that  in  the  higher  pressures  of  a  steam  cycle 
a  reciprocating  engine  has  an  advantage,  while  in  the  lower  pres- 
sures a  steam  turbine  is  more  efficient.  Combine  them,  he  re- 
marks, and  use  each  where  it  is  the  more  profitable.  But  in  his 
view  for  the  utmost  economy  a  new  type  of  plant  should  unite 
both  steam  and  gas  driven  units. 

"Over  a  year  ago,"  he  says,  "while  watching  the  effect  of 
putting  a  large  steam  turbine  having  a  sensitive  governor  in  con- 
nection with  reciprocating  engine-driven  units  having  sluggish 
governors,  it  occurred  to  me  that  here  was  the  solution  of  the  gas 
engine  problem ;  for  the  turbine  immediately  proceeded  to  act  like 


EXHAUST  STEAM  UTILIZED         471 

an  ideal  storage  battery ;  that  is,  a  storage  battery  whose  potential 
will  not  fall  at  the  moment  of  taking  up  load,  for  all  the  load 
fluctuations  of  the  plant  were  taken  up  by  the  steam  turbine,  and 
the  reciprocating  engines  went  on  carrying  almost  constant  loads, 
whilst  the  turbine  load  fluctuated  between  nothing  and  8,000  kilo- 
watts in  periods  of  less  than  ten  seconds. 

'The  combination  of  gas  engines  and  steam  turbines  in  a  single 
plant  promises  improved  efficiency  whilst  removing  the  objection 
to  the  gas  engine,  namely,  its  inability  to  carry  heavy  overloads. 
A  steam  turbine  can  easily  be  designed  to  take  care  of  100  per 
cent,  overload  for  a  few  seconds;  and  as  the  load  fluctuation  in 
any  plant  will  probably  not  average  more  than  25  per  cent,  with  a 
maximum  of  50  per  cent,  for  a  few  seconds,  it  would  seem  that  if 
a  plant  were  designed  to  operate  normally  with  one  half  its  ca- 
pacity in  gas  engines  and  one  half  in  steam  turbines,  any  fluctua- 
tions of  load  likely  to  arise  in  practice  could  be  taken  care  of." 

Discussing  in  detail  the  performance  of  such  a  plant,  Mr.  Stott 
concludes  that  its  average  total  thermal  efficiency  would  be  24.5 
per  cent.,  as  against  10.3  per  cent,  in  the  plant  whose  record  he 
had  presented. 

In  the  bill  of  particulars  drawn  up  by  Mr.  Stott  it  was  shown 
that  no  less  than  60.  i  per  cent,  of  the  total  heat  from  his  fuel  had 
gone  into  the  condenser  where,  joined  to  the 
stream  of  the  East  River,  it  had  been  wasted.        Heating  and 

Had  he  used  non-condensine  motors  the  loss  in 

tion  United. 
exhausts  would  have  been  larger,  and  yet  when 

a  non-condensing  motor  is  joined  to  a  heating  plant  the  whole 
investment  may  be  much  more  profitable  than  where  condensing 
motors  throw  away  all  the  heat  of  their  exhausts.  Long  ago  some 
pioneer  of  unrecorded  name,  using  a  non-condensing  steam  en- 
gine, warmed  his  factory  or  mill  with  its  exhaust  steam.  In  sum- 
mer that  steam  sped  idly  into  the  air,  in  winter  it  saved  him  so 
much  coal  that  his  motive  power  cost  him  almost  nothing.  By 
thus  uniting  the  production  of  power  and  heat  he  showed,  as  few 
men  have  shown,  how  a  great  waste  may  be  exchanged  for  a  large 
profit.  In  the  Northern  States  and  in  Canada  the  main  use  for 
fuel  is^for  heating  not  only  dwellings,  but  the  furnaces  that  pour 
out  iron  and  steel,  the  ovens  that  bake  pottery,  tiles,  and  so  on. 


472 


FUEL  ECONOMY 


When  but  moderate  temperatures  are  desired,  as  in  warming  a 
house,  exhaust  steam  serves  admirably,  and  so  might  the  exhausts 
from  gas  engines.  Indeed  we  here  strike  the  key-note  of  modern 
fuel  economy  which  is  that  wherever  possible  fuel  should  first 
deliver  all  the  motive  power  that  can  be  squeezed  out  of  it,  when 
and  only  when  the  remainder  of  its  heat,  much  the  larger  part  of 
the  whole,  should  be  used  for  warming.1  This  plan,  already 
adopted  in  a  good  many  cases,  can  be  vastly  extended  with  profit. 
In  blast  furnaces  the  first  task  of  the  fuel  is  performed  at  an  ex- 
treme temperature ;  that  work  completed  the  gases  of  combustion 
may  be  purified  and  sent  into  gas  engines  to  produce  motive  power 
at  little  cost. 

A  word  was  said  on  page  380  regarding  the  method  now  grow- 
ing in  favor  for  heating  machine-shops  by  sending  warmed  air 
where  it  is  needed,  and  not  allowing  it  to  go 
Heating  and        where  it  would  proceed  of  itself  and  be  wasted. 
y      Two  illustrations  show  a  Sturtevant  ventilating 
fan-wheel,  without  its  casing,  and  a  Monogram 
exhauster  and  solid  base  heater,  as  used  in  many  modern  installa- 
tions.   The  net  gain  in  send- 
ing warmed  air  just  where  it 
does  most  good  is  comparable 
with  the  profit  in  mechanical 
draft  for  a  furnace  as  com- 
pared    with     natural     draft. 
Either  live  or  exhaust  steam 
may  be  used   in   the  heating 
coils  through  which  the  air  is 
forced  by  the  fan.     See  also 
illustration  on  page  380. 

Steam  plants  which  fur- 
nish both  heat  arid  electricity 
are  being  rapidly  multiplied 


Sturtevant  fan-wheel,  without 
its  casing. 


1  An  excellent  work,  'The  Heating  and  Ventilating  of  Buildings,"  by 
Rolla  C.  Carpenter,  professor  of  experimental  engineering,  Cornell  Uni- 
versity, is  published  by  John  Wiley  &  Sons,  New  York.  Fourth  edition, 
largely  rewritten  and  fully  illustrated.  1902,  $4.00.  It  incidentally  de- 
scribes the  best  methods  of  heating  with  exhaust  steam. 


DISTRICT  STEAM  HEATIXG 


473 


throughout  America.  In  many  cases  these  plants  supply  a  single 
large  hotel,  or  office  building.  The  installation  at  the  Mutual  Life 
Building,  New  York,  is  of  2400  horse-power,  vying  in  dimensions 
with  many  a  central  plant. 
In  Fostoria  and  Springfield, 
Ohio,  in  Milwaukee,  Atlanta 
and  other  large  cities,  a  cen- 
tral station  provides  heat  and 
light  and  motive  power  to  a 
considerable  district. 

At  Lockport,  New  York,  a 
city  of  about  20,000  popula- 
tion, more  than  350  dwellings 
and  business  premises  are 
heated  by  the  American  Dis- 
trict Steam  Company,  a  con- 
cern which  has  installed  more 
than  250  similar  plants 
throughout  the  Union.  The 
advantages  of  this  system 
are  plain  : — cleanliness  is  pro- 
moted ;  customers  handle  no 

coal  or  ashes,  tend  no  fires  or  boilers ;  the  heat  is  more  steadily 
and  equably  supplied  than  if  it  came  from  individual  boilers ;  heat 
is    ready    day    or    night    during    the    heating 
season ;  the  hazard  from  fire  is  lowered  and       District  Steam 
the    risk    of    boiler    explosion    is    abolished;  Heating, 

water  may  be  heated  for  laundries,  bath- 
rooms and  kitchens.  Cheap  fuel  may  be  used,  and  stoked  by  ma- 
chinery. An  individual  boiler  in  a  building  has  to  be  large  enough 
for  its  heaviest  duty ;  in  many  cases  it  is  called  upon  for  but  one 
tenth  to  one  fifth  of  its  full  power,  with  much  incidental  waste. 
At  a  central  station  only  as  many  boilers  of  a  group  are  employed 
at  a  time  as  may  be  worked  to  their  full  capacity,  responding  to 
the  demands  of  the  weather. 

At  Lockport  the  steam-pipes  are  of  wrought  iron  covered  with 
sheet  asbestos  and  enclosed  in  a  round  tin-lined  wood  casing,  hav- 
ing a  shell  4  inches  thick,  with  a  dead  air  space  of  about  one  inch 


Sturtevant    Monogram    exhauster 
and  solid  base  heater. 


474  ISOLATED  PLANTS 

between  the  tin  and  the  asbestos.  In  its  largest  size  this  pipe  has 
shown  a  total  loss  by  radiation  and  conduction  of  but  one  part  in 
four  hundred  in  one  mile ;  for  the  same  distance  the  smallest  pipe 
has  suffered  a  loss  of  six  per  cent.  Live  steam  is  used  at  Lock- 
port,  but  as  a  rule  heating  plants  are  supplied  with  exhaust  steam. 
When  intensely  cold  weather  prevails  this  may  be  supplemented 
by  boilers  in  reserve  which  supply  live  steam. 

It  is  worth  while  to  remark  the  tendency  to  unify,  on  lines  of 
the  best  economy,  a  service  of  both  heat  and  electricity.  In  At1 
lanta  there  were  recently  in  operation  twenty-two  isolated  electric 
plants.  The  central  station  installed  a  steam  heating  system,  and 
as  a  result  in  less  than  a  year  all  but  two  of  the  isolated  plants 
went  out  of  business. 

The  success  of  the  central  station  at  Atlanta  is  due  to  the  mod- 
erate scale  of  its  charges.  In  the  past  there  has  been  some  com- 
plaint of  the  rates  levied  by  central  stations. 

Isolated  Plants.  In  the  future  this  complaint  is  likely  to  di- 
minish, because  an  isolated  plant  for  the  pro- 
duction of  heat  and  electricity  was  never  before  so  low  in  cost,  so 
efficient  in  working,  as  to-day.  Well  managed  central  stations 
broaden  their  market  by  putting  a  premium  upon  the  utmost  pos- 
sible use  of  electricity.  In  Brooklyn,  for  example,  the  Edison 
Electric  Company  charges  10  cents  per  horse-power  hour  to  cus- 
tomers using  100  to  250  horse-power  hours  per  month ;  as  con- 
sumption increases  so  do  discounts  until  the  customer  who  buys 
5 ,000  horse-power  hours  pay 54  cents.  The  demand  for  current  in 
all  its  diverse  applications  is  stimulated  with  energy  and  address. 
A  house  or  apartment  of  seven  rooms  is  wired  for  twelve  lights, 
with  all  fixtures  complete,  for  $95.  Signs  for  advertising  pur- 
poses are  provided  gratis,  on  condition  that  they  be  lighted  by  the 
Company.  The  economy  of  a  small  ice  machine  or  a  refrigerator 
is  pointed  out  all  summer  long,  while  in  winter  the  comfort  and 
convenience  of  electric  heat  is  as  plainly  kept  before  the  public. 
Such  a  policy  as  this  takes  accouin  of  the  irrepressible  facts  of 
present  day  competition.  When  gas  was  the  sole  illuminant,  pro- 
ducible only  on  a  vast  scale,  served  by  an  elaborate  scheme  of 
piping  that  from  the  nature  of  the  case  fell  into  a  single  hand, 
there  was  a  liability  to  extortion.  To-day  in  towns  and  cities  elec- 


GAS  FOR  ALL  SERVICES  475 

tricity,  the  chief  source  of  light,  can  be  ground  out  anywhere 
simply,  cheaply  and  without  offence,  incidentally  affording  when 
desired  almost  as  much  heat  as  if  the  fuel  had  been  burnt  to  pro- 
duce nothing  else.  Among  the  gifts  bestowed  by  the  electrician 
not  the  least  is  this  conferring  at  the  lowest  price  two  prime  neces- 
sities of  life.  But  however  liberal  the  management  of  a  central 
station,  many  a  fat  plum  will  remain  outside  its  pudding.  A  huge 
hotel,  an  office-building,  factory,  or  department  store,  is  best 
served  by  a  plant  of  its  own  designed  to  furnish  both  heat  and 
electricity,  in  which  case  the  electric  current  will  cost  much  less 
than  if  bought  from  a  central  station. 

On  occasion  an  isolated  plant  supplies  a  neighborhood,  and  at 
prices  lower  than  those  of  a  large  central  station  which  may  be  at 
a  considerable  distance.  At  Newark  in  the  New  Jersey  Freie 
Zeitung  building  a  400  kilowatt  plant  is  installed  which  supplies 
the  neighbors  in  two  blocks  with  electricity  at  6  to  8  cents  per 
kilowatt  hour,  according  to  the  extent  of  their  consumption.  A 
necessary  conduit  crosses  Campbell  Street  in  this  service.  It 
seems  likely  that  small  power-centres  of  this  kind,  requiring  no 
franchise,  may  be  common  in  the  near  future,  especially  if  united 
with  heating  systems.  An  inviting  field  for  such  installations  is 
in  the  new  residential  quarters  of  our  cities  and  towns,  where  in 
many  cases  a  whole  block  might  be  cheaply  and  effectively  served 
from  a  single  plant. 

Heat,  light  and  motive  power  may  be  provided  either  by  steam 
or  by  gas.    Modern  industry  does  not  tie  itself  to  any  particular 
servant,  but  chooses  in  turn  whichever,  under 
the  circumstances  of  a  case,  will  serve  it  well  at       Gas  for  Heat, 
least  cost.    Where  natural  gas  is  to  be  had  at  a    Light  and  Power, 
low  price  it  holds  the  field.    But  the  area  thus 
favored  is  small,  so  that  producer  gas  is  employed  on  a  much 
larger  scale.    We  have  already  seen  (page  461)  how  coal  may  be 
gasified,  valuable  by-products  seized,  and  a  cheap  gas  be  piped  for 
miles  with  no  liability  to  the  condensation  which  befalls  steam, 
while  available  for  heating  and  for  motive  power.    When  this  gas 
burns  at  a  fairly  high  temperature,  as  does  Dowson  gas,  it  gives 
with  thorium  mantles  a  good  light,  so  as  to  be  an  all  round  rival 
of  electricity.     Producer  gas  is  preferable  to  solid  coal  because 


476  CENTRALIZED  SERVICES 

perfectly  clean;  it  banishes  the  smoke  nuisance,  and  is  regulated 
by  a  touch.  Mr.  F.  W.  Harbord  in  his  work  on  Steel  (see  page 
177),  says :- 

"The  ease  with  which  perfect  combustion  of  a  gas  can  be  ob- 
tained by  regulating  the  supply  of  gas  and  air,  the  readiness  with 
which  it  can  be  conducted  to  any  required  point,  superheated  or 
burned  under  pressure,  made  to  give  an  oxidizing  or  a  reducing 
flame  at  pleasure,  and  the  general  control  that  can  be  exercised 
over  the  size  and  temperature  of  the  flame,  in  most  cases  more 
than  compensate  for  the  reduction  in  heat  units  due  to  gasifica- 
tion. .  .  .  The  necessity  for  superheating  the  fuel,  and  for 
keeping  solid  fuel  out  of  contact  with  the  bath  of  metal,  make 
gaseous  fuel  indispensable  in  the  open  hearth  furnace,  and  until 
Siemens  solved  the  problem  of  cheap  gasification  of  coal,  this  pro- 
cess of  steel-making  was  impossible." 

Gaseous  fuels  are  employed  not  only  in  steel  making  but  in  the 
manufacture  of  glass,  pottery,  chemicals,  and  much  else. 

When  gas  is  used  in  gas  engines  to  produce  motive  power,  the 
exhausts  having  high  temperatures  may  be  profitably  applied  to 
heating  water,  or  raising  steam,  for  warming  purposes. 

Whether  central  stations  employ  steam  or  gas,  or  unite  both,  it 
is  certain  that  a  unification  of  the  service  of  heat,  light,  and 
motive  power  including  that  required  for  traction,  would  in  all 
our  towns  and  cities  be  attended  by  great  economy,  by  the  aboli- 
tion of  much  discomfort  and  unnecessary  drudgery.  A  large  city, 
such  as  New  York  or  Chicago,  could  be  supplied  with  these  three 
cardinal  necessities  from  comparatively  few  centres. 

Such  centres  may,  before  many  years  elapse,  be  found  stretching 

out  into  the  distant  suburbs  of  cities,  and  linking  town  to  town. 

This  chiefly  because  electricity  has  become  a 

Electric  formidable  rival  to  steam  in  interurban  locomo- 

Traction.  ^Qn       By    thg    time    thig    page    Js    pr'miQ^    the 

New  York  Central  &  Hudson  River  Railroad  will  have  begun 
operating  its  suburban  trains  from  New  York  by  electricity.  For 
this  service  locomotives  built  by  the  General  Electric  Company, 
Schenectady,  New  York,  will  be  in  commission.  Each  will  de- 
velop 2,200  to  3,000  horse-power.  In  careful  tests  a  locomotive 
of  this  kind  reached  a  speed  of  fifty  miles  an  hour  in  127  seconds, 


OF  THE 

UNIVERSITY 


ELECTRIC  LOCOMOTION  477 

whereas  a  "Pacific"  steam  locomotive  required  203  seconds;  an 
important  difference,  especially  where  stops  are  frequent.  Each 
locomotive,  with  its  train  of  cars,  weighed  513  tons.  The  steam 
locomotive  with  its  tender  weighed  171  tons;  its  electric  rival 
weighed  but  100  tons.  So  much  for  the  gain  in  leaving  both 
furnace  and  boiler  at  home,  while  their  power  is  received  through 
a  special  rail  at  rest. 


CHAPTER  XXXII 
A  FEW  SOCIAL  ASPECTS  OF  INVENTION 

Why  cities  gain  at  the  expense  of  the  country  .  .  .  The  factory  system  .  .  . 
Small  shops  multiplied  .  .  .  Subdivided  labor  has  passed  due  bounds 
and  is  being  modified  .  .  .  Tendencies  against  centralization  and  mo- 
nopoly .  .  .  Dwellings  united  for  new  services  .  .  .  Self-contained 
houses  warmed  from  a  center  .  .  .  The  literature  of  invention  and  dis- 
covery as  purveyed  in  public  libraries. 

IN  the  closing  chapter  of  this  book  it  may  be  permissible  to 
glance  for  a  moment  at  a  few  of  the  social  and  national  con- 
sequences of  invention.  While,  as  we  have  seen  in  earlier  chap- 
ters, the  economic  gains  of  ingenuity  surpass  computation,  the 

work  of  the  inventor  has  brought  in  its  train 
The  Drift  evil  as  well  as  good,  and  this  evil,  with  the 
to  Cities.  further  march  of  invention,  is  being  plainly 

lessened  year  by  year.  A  century  ago  about 
one  tenth  of  the  people  in  North  America  lived  in  cities  and 
towns ;  to-day  these  centers  of  population  hold  nearly  one  half 
the  families  of  the  continent.  Many  observers  regard  this  drift 
from  country  to  city  and  town  with  dislike  and  alarm,  without 
recognizing  it  to  be  inevitable.  They  paint  pictures  of  country 
folk  attracted  by  the  superficial  allurements  of  the  city,  a  poor 
exchange  for  the  wholesomeness  and  freedom  of  life  in  the  coun- 
try. They  argue  that  with  wise  education  the  boys  and  girls 
reared  on  the  farm  will  remain  there,  greatly  to  the  gain  of  them- 
selves and  the  nation.  These  critics  leave  out  of  view  the  feats 
of  the  inventor.  Between  1870  and  1880  the  self -binding 
harvester  was  perfected  and  introduced.  Before  its  advent  six 
or  seven  men  followed  every  harvester  to  tie  its  shocks  of  grain. 
After  the  self-binder  came  into  vogue,  five  of  these  men  were  no 
longer  needed.  Other  inventions,  planters,  corn-shellers,  and  the 
like,  as  economical  of  labor,  have  been  placed  in  the  farmer's 

478 


COMFORTS  INCREASED  479 

hands  within  the  past  thirty  years.    The  result  being  that  to  raise 
on   farms  the  food   for  a  million  men,  women  and  children,  a 
greatly  reduced  staff  in  the  field  suffices  to-day  in  comparison 
with  the  number  required  thirty  or  forty  years  ago.    And  what 
has  become  of  the  country  population  thus  thrown  out  of  work 
by  thews  of  steel  and  brass?     It  has  quietly  betaken  itself  to 
towns  and  cities  where,  for  the  most  part,  it  is  manufacturing 
new  comforts  and  luxuries  for  all  the  people,  whether  in  town  or 
country.     In  1870  out  of  100  wage-earners  in  the  United  States, 
29  were  engaged  in  manufactures,  trade  and  transportation;  in 
1900  the  corresponding  figure  had  risen  to  40.    Enter  this  morn- 
ing the  house  of  a  thrifty  farmer  or  mechanic:  you  tread  on  a 
neat  carpet,  you  see  good  furniture,  a  piano  in  the  parlor,  a  bicycle 
in  the  barn.     On  the  walls  are  attractive  pictures,  flanked  by 
shelves  of  books  and  magazines.     In  not  a  few  such  houses  one 
may  find  a  telephone  and  electric  lamps.     As  recently  as  1870 
some  of  these  things  did  not  exist  at  all,  even  for  the  rich.    To- 
day they  are  enjoyed  by  millions.    So  with  clothing:  it  is  to-day 
better  and  cheaper  than  ever  before.     Food,  too,  is  more  varied 
and  more  wholesome  than  of  yore,  thanks  to  the  express  train, 
the  quick  steamer,  the  cold  storage  warehouse.    All  these  agencies 
of  betterment,  and  many  more,  are  conducted  in  cities  as  the 
centers  of  capital,  industry  and  population.  While  invention  has, 
in  the  main,  tended  to  make  cities  bigger  than  ever,  it  is  now 
modifying  that  tendency  by  its  rapid  trolley  lines  to  suburbs,  its 
steamboat  and  railroad  services  constantly  quickened  in  pace  and 
lowered  in  fares.     On  the  outskirts  of  Greater  New  York  it  is 
still  possible  for  a  wage-earner  to  buy  land  for  a  house  and  small 
garden,  the  burden  of  rent,  liable  to  yearly  increase,  being  escaped 
for  good  and  all. 

It  was  in  England  toward  the  end  of  the  eighteenth  century  that 
inventors  first  lifted  the  latch  for  an  industrial  revolution.   When 
James  Watt  devised  his  steam  engine,  and  its 
power  was  applied  to  spinning  and  weaving,        The  Factory 

these  tasks  were  driven  from  the  home  to  the         System  and 
-  Checks  Thereto, 

factory,   there   to  be   more   economically  per- 
formed. Other  industries  followed,  all  the  way  from  paint  grind- 
ing to  nail  making,  so  that  in  a  few  years  a  profound  change  came 


480    SOCIAL  ASPECTS  OF  INVENTION 

over  the  field  of  labor.  Under  a  scheme  of  subdivided  toil  the  fac- 
tory hand  succeeded  to  the  journeyman  who,  with  a  few  mates,  had 
split  nails  or  drawn  wire  in  a  shop  no  bigger  than  some  day  he 
might  own  for  himself.  With  the  need  to  occupy  large  premises, 
to  install  engines  and  elaborate  machinery,  the  capital  of  an  em- 
ployer has  to  be  vastly  more  than  of  old,  creating  a  new  depen- 
dence on  the  part  of  the  workman,  and  rendering  it  all  but  im- 
possible that  he  should  ever  have  a  factory  of  his  own.  While 
the  factory  system  of  production  is  general  in  America,  it  is  far 
from  universal.  Many  leading  manufactures,  those  of  textiles, 
of  boots  and  shoes,  and  so  on,  are  usually  conducted  in  factories, 
while  some  important  industries,  that  of  clothing,  for  example, 
are  for  the  most  part  carried  on  at  the  homes  of  work  people,  or 
in  small  shops.  Massachusetts  in  1900,  according  to  the  U.  S. 
census  of  that  year,  had  200,508  hands  in  1078  textile  mills  and 
boot  and  shoe  factories.  Apart  from  these  industries  were  28,102 
factories  and  shops,  employing  291,418  hands,  an  average  of  but 
10.57  each.1  Taking  the  United  States  as  a  whole,  the  census  for 
1900  reports  that  the  hand  trades  in  small  shops  representing  a 
product  of  $500  or  less  each,  numbered  127,419.  Presumably  in 
all  these  cases  the  worker  toiled  by  himself,  usually  as  a  repairer 
or  a  jobber  rather  than  as  a  maker  of  new  wares.  All  the  other 
manufacturing  concerns,  512,675  in  number,  employed  on  an 
average  only  10.36  persons  each.  It  is  clear  that  the  American 
factory  is  not  as  engulfing  as  many  critics  believe  it  to  be.  In 
larger  measure  than  is  commonly  supposed  workmen  are  to-day 
their  own  masters,  or  are  busy  in  shops  small  enough  to  give 
scope  to  individual  ingenuity  and  skill. 

Let  us  grant  that  a  shoemaker,  say  in  St.  Louis,  at  work  in  a 
stall  of  his  own  is  a  better  and  happier  man  than  if  in  a  nearby 
factory  he  fastened  eyelets,  or  burnished  heels,  day  in  and  day  out 
for  years  together.  While  the  harm  to  the  toiler  wrought  bv 
extreme  subdivision  of  labor  is  plain,  its  evils  are  being  abated 
in  more  ways  than  one.  First  of  all  the  productiveness  of  the 
modern  factory  has  so  augmented  the  joint  dividend  of  capital 

1  Quoted  by  Edward  Atkinson  in  a  paper  on  the  tendencies  of  manufac- 
turing. American  Social  Science  Association,  1904. 


VERSATILITY  SOUGHT 

and  labor  that  while  the  working  day  grows  shorter,  wages  are 
increased,  every  earned  dollar  buying  more  manufactured  wares 
than  ever  before.  Secondly,  in  some  large  railroad  and  other 
shops  the  workmen  are  given  a  variety  of  tasks  in  succession,  so 
as  to  be  more  versatile,  more  useful  in  emergencies,  than  if  ever 
punching  steel,  or  threading  bolts.  Even  if  the  result  of  such  a 
plan  is  to  diminish  the  total  output  in  the  course  of  a  year,  it  is 
worth  while  to  lose  some  money  that  human  nature  may  be  re- 
deemed from  stupefying  monotony  of  toil.  High  wages  and 
large  dividends  cost  too  much  when  bought  at  the  expense  of  hurt 
to  muscle,  nerve  and  brain. 

And  a  notable  group  of  artisans,  few  in  number  but  steadily 
increasing,  with  electric  motors  at  their  elbows,  to-day  enjoy  com- 
plete emancipation  from  the  factory  bell.  A 

woodcarver,      bookbinder,      leather      stamper,       Handicrafts 
r  r  .   .  Revived, 

forger  of  ornamental  iron,  rug  weaver,  potter, 

lens  grinder,  or  printer,  can  have  to-day  a  shop  of  his  own  and 
take  pleasure  in  the  chosen  and  constantly  varied  toil  that  gives 
him  bread.  In  their  simpler  forms  the  modern  lathe,  loom,  print- 
ing press,  are  cheap  enough  to  be  within  the  means  of  poor  men, 
while  thejr  product  when  it  displays  taste  and  originality  is  sure 
of  a  market.  In  times  past  Palissy,  Hargreaves,  and  many  an- 
other master  of  a  handicraft,  has  perfected  a  remarkable  inven- 
tion in  a  small  shop.  We  may  expect  the  arts  to  receive  golden 
gifts  in  the  future  from  the  successors  of  these  men,  feeling  as 
they  do  the  stimulus  of  a  broadening  demand  for  work  executed 
on  new  lines  of  excellence. 

Until  within  a   few  years  past  economic   forces  in   America 
threatened  soon  to  place  its  chief  industries  in  the  hands  of  a  few 
men,  so  strong  and  unscrupulous  as  to  be  able 
to  extort  weighty  and  increasing  tribute.     For        Tendencies 

this   danger   remedies  legislative  and   judicial  Against 

,    .  ,  .  ,  Centralization, 

are  being  sought,  with  the  prospect  of  eventual 

success.  In  this  place  it  may  be  allowable  to  remark  how  the 
progress  of  invention  is  working  hand  in  hand  with  the  aims  of 
social  justice.  In  the  pages  immediately  preceding  this  chapter 
we  have  seen  how  cities  and  towns  are  working  themselves  loose 
from  monopoly.  A  gas  supply,  on  the  old  basis  of  manufacture 


482   SOCIAL  ASPECTS  OF  INVENTION 

at  least,  must  be  a  unit,  with  a  strong  temptation  to  overcharge 
its  customers.  To-day  the  lighting  field  is  shared  with  electricity, 
showing  many  isolated  plants ;  when  these  purvey  heat  as  well  as 
light  their  rivalry  with  central  stations  may  become  formidable. 
In  American  villages  and  small  towns  the  principal  source  of  light 
is  petroleum,  largely  controlled  by  the  Standard  Oil  Company. 
From  its  exactions  there  opens  escape  as  the  farmer  finds  a  source 
of  cheap  alcohol  in  his  corn,  potatoes  and  beets,  even  in  his  un- 
marketable fruit  or  damaged  grain,  ready  to  give  him  more  light 
than  petroleum  ever  did,  and  besides  propel  his  machinery,  or 
carry  his  crops  to  the  nearest  market  town.  The  betterment  of 
common  roads  throughout  the  Union  proceeds  in  earnest.  As 
that  reform  goes  forward  we  may  see  motor-driven  cars  and 
wagons  exerting  a  restraining  influence  on  local  railroad  rates. 
Already  the  steam  railroads  are  facing  keen  competition  from  in- 
terurban  electric  lines.  Wherever  these  lines  resist  absorption, 
or  control,  by  the  steam  carriers  they  serve  the  farmer  so  well 
and  cheaply  as  to  be  one  of  the  chief  boons  he  has  received  at  the 
inventor's  hands. 

Take  one  instance  chosen  from  many  as  striking.  Dayton, 
Ohio,  is  a  center  of  interurban  lines  which  enfold  in  their  sweep 
Urbana,  Columbus,  Hamilton  and  Cincinnati.  Upon  220  miles 
of  these  lines  the  Southern  Ohio  Express  Company  picks  up  cans 
of  milk,  cases  of  eggs,  crates  of  berries,  packages  of  tobacco, 
from  a  thousand  farmsteads.  In  the  larger  business  of  carrying 
grain  and  live  stock  the  expansion  is  constant,  so  that  the  day 
seems  near  at  hand  when  the  company  will  find  profit  in  placing 
a  switch  at  every  farm  along  its  lines,  sending  cars  there  for 
everything  the  farmer  has  to  sell.  And  the  countryman  finds 
Dayton  as  good  a  place  to  buy  in  as  to  sell  in ;  its  merchants  offer 
better  and  cheaper  wares  than  are  to  be  had  in  the  home  village 
or  the  neighboring  small  town.  To-day  a  farmer  or  market- 
gardener,  a  dairyman  or  stockbreeder,  does  not  find  the  smallness 
of  his  capital  the  drawback  it  would  have  been  ten  years  ago. 
With  an  interurban  line  passing  near  his  home,  or  in  front  of  his 
door,  with  a  cheap  telephone  at  hand,  and  enjoying  a  free  rural 
mail  delivery,  he  can  sell  his  produce  when  he  pleases  and  at  the 
best  market  prices,  paying  but  a  light  tax  to  the  middleman,  cr 


DWELLINGS  IMPROVED  483 

completing-  a  transaction  with  a  directness  that  leaves  the  middle- 
man out  altogether. 

Steam  railroads  seek  large  trainloads  to  be  moved  long  dis- 
tances; an  electric  freight  and  express  service  coins  dimes  into 
dollars  by  picking  up  market  baskets,  bundles  for  the  seamstress 
and  the  laundress,  a  bunch  or  two  of  saplings  for  the  orchard. 
The  trunk  lines  of  America,  with  their  wide-spreading  branches, 
enable  merchants  in  the  cities  and  the  larger  towns  to  replenish 
their  counters  and  shelves  every  day.  Stocks,  therefore,  need  not 
be  so  large  as  of  old,  when,  let  us  say,  a  whole  winter's  goods 
were  laid  in  by  October.  The  change  reduces  the  amount  of  capital 
required,  the  outlays  for  rent  and  insurance,  the  liability  to  shrink- 
age and  deterioration  of  values.  The  interurban  roads  are  extend- 
ing these  advantages  to  the  village  storekeeper  who,  in  the  morn- 
ing telephones  his  wants  to  Toledo,  Cleveland,  or  Detroit ;  and  in 
the  afternoon  disposes  the  ordered  wares  on  his  shelves.1 

American  dwelling  houses,  whether  in  city  or  country,  have 
within  forty  years  been  much  improved  in  plan  and  equipment. 
To  speak  only  of  dwellings  in  cities,  we  may 
note  how  designers  and  inventors  have  pro-       New  Domestic 
moted  comfort  and  convenience,  health  fulness        Architecture, 
and  cheer.     At  the  close  of  the  Civil  War  an 
ordinary  house  in  Philadelphia,  or  Chicago,  as  it  left  the  builder's 
hands  was  little  else  than  a  bare  box.     Stoves  for  warming  and 
cooking  had  to  be  brought  into  it,  wardrobes  heavy  and  clumsy 
were  placed  beside  its  walls,  cupboards  meant  to  be  moved  and 
not  moved  easily  held  the  raiment  and  table  linen.     In  rented 
houses  the  gas  fixtures  might  belong  to  the  tenant ;  when  he  took 
them  away  ugly  breaks  appeared  in  walls  and  ceilings.     To-day 
all  this  is  of  the  past:  in  important  details  the  design  of  the 
mansion  is  embodied  in  dwellings  comparatively  small.    Furnaces 
for  heating,  ranges  for  cooking,   form  part  and  parcel  of  the 
building ;  fixtures  for  gas  and  electricity,  yielding  both  light  and 
heat,  are  provided  just  as  water  faucets  are;  every  bedroom  has 
its  clothes  closet  instead  of  the  lumbering  wardrobe.     In  the 
kitchen  we  find  dressers  and  china  closets  built  into  the  walls; 

1  Outlook,  New  York,  January  7,  1905. 


484    SOCIAL  ASPECTS  OF  INVENTION 

the  laundry  has  stationary  washtubs  and,  in  some  cases,  a  drying 
room  as  well,  so  that  the  laundress  does,  not  care  should  it  rain  on 
washing  day.  The  aim  throughout  is  that  the  house  and  its 
equipment  shall  as  far  as  possible  make  up  a  unit,  that  the  labor 
of  housekeeping  be  minimized  to  the  utmost  by  a  judicious  outlay 
of  capital  when  the  house  is  built. 

Since  1900  the  American  householder,  as  well  as  the  American 

business  man,  has  fairly  awakeaed  to  what  the  telephone  can  do 

for  him.     It  is  estimated  that  in  1905  the  tel- 

Electricity  at  ephone  in  the  United  States  earned  four  times 
as  much  as  the  telegraph.  T-he  day  is  at  hand 
when  -every  household  but  the  poorest  will  enjoy  the  wonderful 
gift  of  Professor  Bell.  In  somewhat  the  same  fashion  it  is  dawn- 
ing upon  the  public  that  electricity  stands  ready  to  perform  other 
services,  each  minor,  but  all,  in  the  aggregate,  going  far  to  pro- 
mote health  and-  comfort  at  home. 

At  Schenectady,  New  York,  Mr.  H.  W.  Hillman,  apart  from 
heating  in  winter,  has  adopted  electricity  for  many  household 
tasks,  wi-th  results  described  and  illustrated  in  the  Technical 
World,  Chicago,  July,  1906.  His  kitchen  outfit  for  a  family  of 
five  persons  comprises  an  electric  table,  oven,  griddle-cake  cooker, 
meat  broiler,  cereal  cooker,  water  heater,  egg  boiler,  potato 
steamer,  frying  pan,  coffee  percolator,  and  a  stove  for  ordinary 
cooking  utensils.  A  three  pound  nickel  plated  electric  iron  is  pro- 
vided for  the  laundry.  In  the  dining-room  is  an  electric  chafing 
dish  and  a  percolator.  On  the  verandah  and  in  the  den  are 
electric  cigar  lighters.  In  the  sewing-room  the  machine  is  driven 
by  an  electric  motor.  The  bathroom  has  an  electric  mug  which 
heats  water  for  shaving  in  less  than  a  minute ;  in  chilly  weather 
the  luminous  radiator  yields  just  the  slight  heat  which  ensures 
comfort  instead  of  discomfort.  Of  course,  throughout  the  house 
electric  lamps  furnish  light  with  the  maximum  of  convenience 
and  wholesomeness,  the  minimum  of  risk. 

How  does  this  service  compare  in  cost  with  the  employment  of 
coal  and  gas?  With  coal  at  $6.50  a  ton,  and  gas  at  $1.30  per 
thousand  cubic  feet,  the  average  monthly  expense  was  formerly 
$6.00 ;  with  electricity  the  bills  are  but  69  cents  more  per  month,  a 
mere  trifle  in  comparison  with  the  gain  in  comfort,  the  saving  of 


ELECTRICITY  AT  HOME  485 

drudgery,  the  promotion  of  cleanliness.  The  rate  for  electricity 
used  for  lighting  is  10  cents  per  kilowatt  hour,  for  heating  only 
half  that  rate. 

Mr.  Hillman  does  not  use  electric  heat  for  ordinary  warming: 
it  would  cost  him  too  much.  A  good  many  people  are  puzzled  by 
the  fact  that  an  electric  current,  which  yields  a  perfect  light  at  a 
reasonable  price,  should  in  the  sister  task  of  heating  fail  in  rivalry 
with  a  common  stove  or  furnace.  To  solve  this  puzzle  let  us 
place  our  hands  above  a  cluster  of  15  Edison  incandescent  lamps, 
each  of  16  candle  power,  representing  one  horse  power,  yet  emit- 
ting no  more  heat  than  if  three  ounces  of  coal  were  slowly  burn- 
ing away  in  the  course  of  an  hour.  This  electricity  may  cost  us 
ten  cents  an  hour,  the  coal  costs  but  the  fifteenth  part  of  one  cent. 
In  producing  mechanical  motion  at  a  power-house,  the  engines 
waste  at  least  ninety  per  cent,  of  the  applied  heat.  To  this  heavy 
tax  must  be  added  the  expenses  of  distribution,  administration 
and  maintenance.  Until,  therefore,  the  electrician  reaches  a  mode 
of  creating  his  current  from  heat  without  the  enormous  losses  of 
present  practice,  we  cannot  look  to  him  for  a  system  of  general 
heating.  A  word  has  already  been  said  in  this  book  about  methods 
of  district  heating  by  steam.  Another  plan  is  worthy  of  mention. 
In  Brooklyn  the  Morris  Building  Company  supplies  from  a  cen- 
tral plant  fifty-two  dwellings  with  hot  water  which  serves  not 
only  for  heating,  but  for  cooking  and  washing  also.  The  water 
is  heated  in  part  by  live  steam,  in  part  by  exhausts  from  steam 
engines. 

Such  an  experiment  as  this,  the  appliances  at  work  for  Mr. 
Hillman,  suggest  exhibits  which  might  form  part  of  the  premises 
of  agricultural  colleges  and  technical  schools. 
These  establishments  usually  require  for  their          Suggested 
officers  such  dwellings  as  are  not  too  large  and 
costly  for  ordinary  householders.    These  dwellings,  carefully  de- 
signed and  equipped,  might  serve  as  examples  of  the  best  practice 
in  building,  planning  and  appointment ;  in  sound  methods  of  heat- 
ing from  a  central  plant.    At  suitable  times  they  might  be  open  to 
public  inspection.     They   might   range   in   cost   from   $1,000  to 
$5,000,  the  cheapest  to  be  built  of  wood,  others  to  be  built  in 
brick,  stone,  or  concrete.     All  the  furniture  and  fittings  to  be 


486        LITERATURE  OF  INVENTION 

chosen  with  an  eye  to  wholesomeness,  durability,  and  maintenance 
with  the  least  labor  possible.  Each  house  should  contain  in  its 
main  room  a  card  telling  the  cost  of  the  building,  with  estimates 
of  cost  if  executed  in  other  materials.  On  occasion  this  plan 
might  be  extended  to  the  contents  of  houses,  each  item  on  show 
days  to  be  duly  labeled.  A  series  of  such  houses  would  tend  to 
bring  ordinary  house-planning  and  housekeeping  to  the  level  of 
the  best.  Many  books  and  journals  offer  architectural  diagrams 
which  few  can  understand,  but  everybody  can  see  how  attractive 
a  good  plan  is  when  realized  in  a  house  to  which  he  pays  a 
leisurely  visit.  At  Expositions,  such  as  those  of  Chicago  and  St. 
Louis,  the  appeal  of  the  architect  and  the  exhibitor  is  rather  to 
wonder  than  to  utility.  He  shows  us  schlosses  from  Germany, 
palaces  from  Italy,  chateaux  from  France,  all  appointed  with 
costly  magnificence.  But  while  the  average  American  wage  is 
eleven  dollars  a  week  these  displays  can  do  little  good  as  models 
for  imitation. 


NOTE  ON  THE  LITERATURE  OF  INVENTION  AND 

DISCOVERY 

Books  on  invention  and  discovery  are  mentioned  here  and  there  through- 
out this  volume.  The  reader  may  wish  further  references,  in  which  case 
he  may  find  them  at  the  public  library  nearest  home.  Within  the  past 
few  years  the  public  libraries  of  America  have  been  laying  stress  on  their 
educational  departments,  are  becoming  more  and  more  a  worthy  comple- 
ment to  the  public  schools. 

At  the  Carnegie  Library,  Pittsburg,  the  department  of  technology  is  di- 
rected by  Mr.  Harrison  W.  Craver,  a  graduate  of  a  polytechnical  institute, 
who  has  had  experience  as  a  practicing  chemist.  The  collection  keeps 
mainly  to  lines  of  local  interest,  and  includes  an  ample  array  of  trade 
journals.  Indexes  to  articles  in  technical  journals  are  maintained.  On 
the  shelves  are  files  of  patents  of  the  leading  nations  of  the  world.  Short 
lists  of  books  on  subjects  of  current  interest  are  from  time  to  time  com- 
piled and  issued.  Workers  receive  advice  and  personal  assistance  from 
scientifically  trained  men.  Questions  are  answered  by  mail  and  telephone. 
Notes  on  books  are  appended  to  their  titles  on  the  catalogue  cards,  and  in 
the  monthly  bulletin. 

Mr.  Graver's  aid  extends  to  other  public  libraries,  among  them  to  that 


TRUSTEES  OF  LITERATURE         487 

at  Providence.  Here  the  industrial  department  contains  about  7600  vol- 
umes, chiefly  devoted  to  the  principal  industries  of  the  city, — textiles,  elec- 
trical arts,  machinery,  and  the  arts  of  design,  especially  in  jewelry.  A 
room  is  at  the  service  of  draughtsmen :  a  dark  closet  is  available  for  copy- 
ists who  bring  cameras.  When  a  new  book  comes  in  the  reader  or  the 
artist  likely  to  want  it  is  notified. 

The  Pratt  Institute  Free  Library,  Brooklyn,  has  an  applied  science  refer- 
ence room  which  receives  115  scientific,  technical  and  trade  journals.  It 
has  brought  together  a  large  collection  of  trade  catalogues,  duly  classified, 
and  a  collection  of  cuts  of  machines  and  mechanical  devices.  The  custodian 
makes  it  his  business  to  visit  the  neighboring  factories  and  workshops,  so 
as  to  provide  every  publication  likely  to  be  of  help.  The  use  of  this  de- 
partment increases  steadily,  with  a  marked  effect  on  the  proportion  of 
scientific  books  taken  from  the  general  library  for  home  reading. 

Newark,  a  city  of  many  and  diverse  manufactures,  has  a  public  library 
also  of  the  first  rank.  Scientific  books,  as  received,  are  brought  to  public 
attention  through  the  press,  and  by  means  of  the  monthly  bulletin  mailed 
to  any  one  on  request.  -Short  lists  of  selected  works  on  particular  branches 
of  applied  science  are  prepared  for  gratuitous  distribution :  in  each  book  of 
a  series  the  full  list  is  pasted  as  a  guide  to  extended  reading.  Readers  are 
invited  to  ask  for  any  book  not  in  the  library  which  they  believe  would  be 
of  service  to  them. 

These  are  but  a  few  examples  of  the  work  the  public  libraries  are  doing 
throughout  the  Union.  At  the  headquarters  of  the  American  Library  Asso- 
ciation are  issued  manifold  aids  for  readers  and  students:  a  list  of  them  is 
given  on  a  page  following  the  index  to  this  book.  Let  us  hope  that  one  of 
these  days  the  Association  may  establish  a  bureau  through  which  the 
literature  of  applied  science,  and  all  other  worthy  literature,  may  be  passed 
upon  by  a  staff  of  the  best  critics,  for  the  behoof  of  all  the  people.  Such 
a  service  would  inure  not  only  to  the  good  of  those  who  borrow  books  from 
public  libraries,  but  would  afford  help  to  the  men  and  women  who  buy 
books  for  libraries  of  their  own. 


INDEX 


Abbe,  Ernst,  portrait,  facing  182:  Jena 
glass,  181;  at  first  ignorant  of  prac- 
tical optics,  293. 

Aboriginal  art,  National  Museum,  Wash- 
ington, 1 06;  tools,  89. 

Abrasion,  manganese  steel  resists,   171. 

Accident,  Nobel  profits  by  an,  411. 

Accidental  observation,   289. 

Acheson,  E.  G.,  carborundum,  101. 

Achromatism,  Newton  on,  254. 

Acknowledgments,    xxi. 

Actinium,  four  derivatives,  200. 

Adams,  Frank  D.,  proves  marble  plastic, 
196. 

Adams,  John  Couch,  discovers  Neptune, 
378. 

Aeronautics,  129. 

Air,  compressed.  See  Compressed  air; 
brake  catechism,  R.  H.  Blackall,  428; 
chamber  of  pumps,  252;  churned  in 
telescopic  tube,  348;  compressors,  424- 
427;  and  multiple  cylinders  for,  372; 
turbines,  reversed  as,  372;  conducting 
when  traversed  by  X-ray,  282;  warm, 
and  smoke  protect  from  lightning,  294; 
hardening  steel,  172;  jet  for  machine 
tools,  173. 

Aladdin  oven,  189,  190. 

Alchemy  and  radio-activity,  203. 

Alcohol,  cheap,  452;  engines,  468;  for 
lighting,  157;  lamp  with  hood,  158. 

Algonquin  art,  115. 

Allan  Line  steamers  driven  by  turbines, 
455.  456. 

Allen,   Leicester,  on  invention,  268. 

Allis-Chalmers  steam  engines,  facing  448, 
facing  452;  Francis  vertical  turbine, 
446. 

Alloy  for  electro-magnets,  173. 

Alloys,  influence  of  minute  admixtures, 
175;  made  by  pressure,  W.  Spring, 
201;  Weston's  for  electrical  measurers, 
232,  234;  anti-friction,  174. 

Alternating  currents  used  as  produced, 
346. 

Alum  crystal  broken  and  repaired,  193, 
194. 

Aluminium    discovered    by    Wohler,    143: 

froperties,     143,     144,     145;     separated 
rom    its   compounds    by    C.    M.    Hall; 

uses,    144,    145;   in  lithography,    144;   in 

producing  great  heat,   145;  alloys,   145; 

as    electrical    conductor,     145;    in    iron 

manufacture,     145;     mandolin    pressed, 

185. 

Alundum  wheels,   101. 
American     Library    Association,    aids    to 

readers  and  students,  487. 
Ammeter,  Weston's,  233. 
Ammonia  sulphate  from  Mond  plant,  461. 
Analogy  as  a  guide,  366-369. 
Anderson,  Sir  William,  on  formulae,  38.1. 
Andrews'     discovery     of     continuity     in 

states  of  matter,  212. 


Angles  replaced  by  curves,  48-51. 

Animal  frame  repeated  in  machinery,  250. 

Annealing  steel,   168. 

Annular  drills,  91-93. 

Anthony,  W.  A.,  on  invention,  268. 

Anti-friction  alloys,-  174. 

Ants,  Warrior,  nest,  260. 

Aquarium,  New  York,  76. 

Arbor  hollow,  cooled,  88. 

Arc-lamp,   160;  inverted.  75,  76. 

Arch,  its  structural  advantage,  42;  dis- 
cussed by  W.  P.  P.  Longfellow,  43; 
as  dam,  45;  of  skull,  250;  Saracenic, 


43;    bridge,   Niagara,   31. 
che 
:ho: 
dome,  355. 


Arches     inverted     as     gullcys,     and     an- 
chorage,   45;     pointed,    43;     united    as 


Architecture.  Egyptian,  114;  Japanese, 
Ralph  Adams  Cram,  114,  foot-note; 
materials,  115;  modern,  Russell  Stur- 
gis  on,  119;  new  domestic,  483. 

Areas,  irregular,'  measured,   347. 

Argon  discovered  by  Lord  Rayleigh,  213. 

Arm  holding  ball,  256. 

Arrows,  feathers  in,  65. 

Articulated  water-pipe,  259. 

Ashes,  conveyors  tor,  447. 

Astatic  needles,  149. 

Astronomy  advanced  by  new  instru- 
ments, 230;  aided  by  Carnegie  Insti- 
tution, 277;  co-operation  in,  E.  C. 
Pickering,  278;  measurements  in,  229, 
230. 

Atkinson,  Edward,  Aladdin  oven.  189; 
on  window  glass,  72;  "Science  of  nutri- 
tion," 190;  tendencies  in  manufactur- 
ing, 480,  footnote. 

Atmosphere,  gases  of,  213,  214. 

Atom,    size,    130-32. 

Atwater,  W.  O.,  on  foods,  241;  on  energy 
value  of  foods,  264;  aided  for  re- 
searches on  foods,  277. 

Austenite,   164. 

Automatic  devices,  329-337;  at  Inter- 
borough  Power-house,  447;  stokers,  450. 

Automobile  design,  117;  gasoline  driven, 
construction,  468;  balanced  cylinders, 
464;  racing,  66-  radiator,  87. 

Axe  tells  story,  Wm.   Metcalf,   377. 

Axles,   hollow,   40;  cooled,  88. 

Baboons  teach  Hottentots  and  Bushmen, 
i.3<5,  259. 

Bain,  Alexander,  on  identifying  faculty, 
360;  on  passion  for  experiment,  304; 
on  sound  judgment,  385. 

Balance,  beginnings,  208;  ancient  Egyp- 
tian, 219,  220;  Lavoisier,  209;  inter- 
ferometer applied  to,  217;  measures  ir- 
regular areas,  347;  requirements  for, 
220;  at  its  best,  221. 

Balance  wheel  in  time-pieces,  222;  Earn- 
shaw's  compensated,  223. 

Balances,  Bureau  of  Standards,  335. 


489 


490 


INDEX 


Bale,  Geo.  R.,  Modern  Foundry  prac- 
tice, 176. 

Ball-and-socket  joints,  251. 

Ball  bearings,  47,  48. 

"Baltic,"  steamer,  127. 

Baltimore  truss,  25. 

Bamboo,  its  uses,  141;  for  walls  and 
roofs,  39;  for  water  carriage,  45;  fila- 
ment for  electric  lamp,  140. 

Bank-swallow,  lesson  from,  297. 

Bar  of  metal  shaped  by  pressure,  326; 
for  reinforcing  concrete,  436,  437. 

Bark  vessel  and  clay  derivative,   115. 

Barnard,  E.  E.,  detects  a  double  star, 
285. 

Barrel  pressed  steel,  185. 

Barrett,  W.  F.,  experiments  with  iron 
alloys,  173. 

Basin,  experimental,  for  ship  models,  54, 
55;  U.  S.  Navy,  facing  54. 

Baskerville,  Charles,  researches  in  tho- 
rium, 200. 

Basket,  Bilhoola,  no,  in;  Porno,  109; 
bowl,  Yokut,  112. 

Baskets  imitated  from  fish  traps,  116; 
materials  for,  109-  waterproof,  143. 

Basketry,  materials  for,  142;  Indian,  Otis 
T.  Mason,  no,  142. 

Bates,  W.  H.,  explains  protective  re- 
semblances, 289. 

Bearings,  ball,  47,  48;  roller,  47,  49. 

Beaufoy,  Marc,  on  ship  resistances,  52. 

Beauty  through  use,   104,  105. 

Beaver  dams,  ingenuity  of,  265;  tooth, 
258. 

Becquerel,  Henri,  researches  in  phos- 
phorescence, 199. 

Beethoven  composing,  300. 

Begonia,  tuberous,  produced,   249. 

Bell,  Alexander  Graham,  portrait  frontis- 
piece, facing  is  Brantford  homestead; 
transmission  of  sound  by  light, "  393- 
400;  telephone,  393,  foot-note,  293. 

Bell,  Sir  I.  L.,  manufacture  iron  and 
steel,  177. 

Bell,  Louis,  "Art  of  Illumination,  229, 
foot-note. 

Bergman,  Torbern,  analyzes  steel,  163. 

Bessemer,  Henry,  portrait  facing  402; 
early  tasks,  makes  bronze  powders,  401; 
improves  sugar-cane  mill,  402;  begins 
experiments  with  iron,  403;  first  con- 
verter, 404;  illustrated,  406;  pulverizes 
materials  for  glass,  407;  on  "a  little 
knowledge,"  408;  improves  the  drying 
of  oils,  409;  process,  164;  steel  rails,  14. 

Bicycle  wheel,  382. 

Bi-focal  spectacles,  85. 

Bilgram,  Hugo,  gearing,  67. 

Binding  machinery,   direct,  342. 

Binocular  glasses,  81,  82. 

Biological  observations,  Karl  Pearson  on, 
277;  laboratories,  276. 

Pi'rch-bark  vessels,  115. 

Bird's  feet  covered  with  dirt  observed  by 
Darwin,  280. 

P-ilhoola  basket,   no,   ITT. 

Birds  and  reptiles,  a  link  discovered  by 
E.  S.  Morse,  287;  flight  of,  studied,  263. 

Bismuth  pure  and  united  with  tellurium, 
175. 

Blackall,   R.   H.,  air-brake  catechism,  428. 

Blanchard  lathe,  95-97. 

Blast  furnaces  curved,  50;  gases  for 
power,  462. 


Blasting,  its  utility,  411. 

Blenkinsop's  locomotive,  345. 

Bliss  press  work,  184-186;  forming  die, 
184;  gears,  67. 

Blocks,    hollow   concrete,    433-435. 

Blood,  circulation  of,  256;  pressure,  ex- 
periments on,  272. 

Blowing  machinery,  Homestead,  Pa.,  415. 

Boat,  canal,  diminishes  in  resistance 
when  quickened,  283. 

Boiler  corrugated,  88;  economy,  450;  out- 
side furnace,  381:  plate  cut,  91;  cop- 
per, how  improved  or  worsened,  176. 

Boiling  point  water  lowered  as  atmo- 
spheric pressure  lessens,  375. 

Boivin  burner  for  alcohol,   157. 

Bolometer,  Langley's,  225. 

Bookcases,  sectional,  351. 

Book-shelves  with  camber,  laden  and  un- 
laden, 36,  37,  254. 

Books  reproduced  by  photography,  324. 

Borderlands  of  knowledge,  Lord  Ray- 
leigh  on,  275. 

Bourne,  George,  on  beauty  of  tools,  105. 

Bow-puller  studied  by  E.   S.  Morse,  288. 

Bowstring  bridge,  31;  Philadelphia,  32; 
invented  by  Alex.  Nasmyth,  308. 

Brace,  ratchet  bit,  90. 

Brachiopods  studied  by  E.  S.  Morse,  288. 

Brahe,  Tycho,  observations,  229. 

Brain  in  co-ordination,  257;  disease, 
localization,  378;  disease  treated,  272. 

Brakes,  Westinghouse,  428. 

Bramah,  planer,  98. 

Brashear,  J.  A.,  concave  plates  for  Row- 
land, 237;  optical  surfaces  produced, 
83,  84;  lenses  and  mirrors  for  inter- 
ferometer, 217. 

Breakwaters  curved,   51;   concrete,   430. 

Breech-loader,  379. 

Bricks  shaped  by  pressure,  325. 

Brick- work  outlines,   112. 

Bridge,  concrete,  at  St.  Denis,  431;  For- 
est Park,  St.  Louis,  444;  Memorial, 
Washington,  D.  C.,  444;  continuous 
girder,  32,  34;  deck,  24;  pipe-arch, 
Rock  Creek,  41;  and  at  Saxonville, 
Mass.,  41,  42;  Plauen,  Germany,  42, 
43;  rollers,  38;  St.  Louis,  31;  strains 
studied,  25;  through,  24;  Victoria, 
Montreal,  26-28;  Whipple,  25. 

Bridges,  18-38;  cantilever,  26;  near  Que- 
bec, 29,  30;  Kentucky  river,  30,  31; 
esthetic  designs,  38;  railroad,  23;  sus- 
pension, 32. 

Bronze  powders,  Bessemer's,  401. 

Browne,  Addison,  on  original  research, 
273. 

Brush,  Charles  F.,  arc-lamp,   160. 

Bubbles  rising  in  liquid,  127,  128; 
sharpen  files,  147. 

Buchanan,  William,  plans  famous  en- 
gine, 15. 

Buffalo  trails  give  hints  to  railroad  en- 
gineers, 259. 

Buffon  on  invention,  271. 

Bullock  cart  with  solid  wheels,  47. 

Bulrush  section,   251. 

Bureau  of  Ethnology  reports,  107,  foot- 
note. 

Bureau  of  Standards,  Washington,  234- 
236. 

Burke,  Charles  G.,  telegraphic  code,  352, 
353;  simplified  signals,  354. 

Burner,  Boivin,  for  alcohol,  157. 


INDEX 


491 


Burroughs,   John,   on   observation,   281. 
Bushmen  learn  from  baboons,   136. 
Buttresses  for  arches,  43. 


Cabin,  disadvantages  of  its  size,   130. 

Cables,    electric,    X-rays   examine,    327. 

Cactus  adapts  itself  to  environment,  248. 

Cadmium  rays,  218. 

("aliper,  micrometer,  236. 

Camber  in  book-shelves,  36,  37,  254;  in 
bridges,  37. 

Campbell,  H.  H.,  Manufacture  iron  and 
steel,  177. 

Canada,   roofs  in,   118,    uq. 

Canal  and  circulation  blood,  256;  boat 
diminishes  in  resistance  when  quick- 
ened, 282. 

Candles  copied  in  gas-burners,  116;  and 
in  electric  lamps,  117. 

Cantilever,  26;  bridges,  26-31;  where 
best,  35. 

Capital  more  necessary  under  factory 
system  than  before,  480. 

Carbon  dioxide  detected  in  flue  gases, 
470. 

Carbon  in  steel,  163,  164;  filament  graph- 
itized,  158. 

Carborundum  wheels,  101,  102. 

Carburetor,  466. 

Cards  for  catalogues,  349,  for  notes,  350. 

Carex  root  in  basketry,    no,    143. 

Cargo  steamer,  59,  61. 

Carnegie  Institution  for  Original  Re- 
search, 276-278;  Library,  Pittsburg, 
486. 

Carpenter,  Rolla  C.,  "Heating  and  ven- 
tilating buildings,"  472. 

Cartilage  in  joints,  251. 

Carving  chisels  and  gouges,  90;  by  air 
hammers,  418. 

Catenary  curve,  43. 

Cathode  rays,   198. 

Cattle-breeding,  249. 

Caves  as  store-houses,  137;  Virginia  and 
Kentucky,  123,  246. 

Cedar  for  basketry,  no,  142. 

Ceiling,  heating  coils  on,  86;  white,  as 
reflector,  76. 

Cellulose  filaments   for  lamps,    261. 

Celts  lend  forms  to  bronze,   116. 

Cement,  natural,  430;  Portland,  430; 
Roman,  429. 

Cementite,  164. 

Central  stations,  telephonic,  257;  man- 
agement, Edison  Electric  Co.,  Brook- 
lyn, 474. 

Centralization,  tendencies,  481. 

Cerium  for  gas  mantle,  156. 

Chain  suspended,  43,  44. 

Chaldean  records  of  eclipses,  229. 

Channeling  machine,  Saunders,  342. 

Chanute,  Octave,  on  invention,  268. 

Character  in  research,  Tyndall  on,  364. 

Charcoal,  125;  produces  vacuum,  328. 

Chemical  synthesis,  374;  theory  enlarged 
by  discovery  of  radio-activity,  203; 
triggers,  337. 

Chemistry  of  living  bodies,  262. 

Chimneys,  why  shorter,  448;  reinforced 
concrete,  440,  441. 

Chisel,  carving,  90;  cold,  of  two  kinds 
steel,  167. 

Chittenden,  L.  E.,  lesson  from  bank- 
swallow,  297. 


Church,  Duane  H.,  inventor  watch-mak- 
ing machines,  222. 

Church  of  St.  Remy,  43;  Notre  Dame  de 
Bonsecours,  Montreal,  118. 

Cinders  large  and  small  on  hearth,  120. 

Cities,  why  they  gain  at  expense  of 
country,  478;  sites  for,  246. 

"Class  in  Geometry,"   122. 

Classification  literature,  Melvil  Dewey, 
352. 

Clay  molded,    102,    103;   in  the  arts,    139. 

Cleveland  Stone  Co.,  compressed  air 
plant,  427. 

Clifton   suspension  bridge,  anchorage,  45. 

Clipper  ships,  57. 

Cloaca  Maxima.  Rome,  45. 

Clocks,  Riefler,  223,  224;  self-winding, 
330. 

Coal,  glowing,  broken  into  fragments, 
120;  cutter,  Ingerspll,  418;  testing 
plant,  U.  S.  Geological  Survey,  foot- 
note, 241-  washer,  151. 

Cobbett,  William,  on  writing  as  an  ex- 
citer of  thought,  300. 

Coding  in  telegraphy,  352-354;  in  inven- 
tion, 317. 

Coherer,  origin  of,   147. 

Coignet  netting   for  concrete,  442. 

Coils,  heating,  86. 

Collections,  value  of,  288. 

Collodion,  Nobel  utilizes,  411. 

Color  dispersion,   180. 

Columns  of  bridge,  23;  hollow,  39. 

Combinabilitv  of  matter,  194. 

Compass  deflected  by  electricity,  230,  231, 
290. 

Compasses  as  truss  model,  20;  liquid, 
149. 

Compensating  devices,   148. 

Complexity  in  machine  may  be  neces- 
sary, 341. 

Compressed  air,  417-428;  drives  tools, 
417;  coal  cutter,  418;  for  hammers, 
facing  418,  419;  air  tools  first  used 
by  dentists,  419;  drill  used  as  ham- 
mer, wood-borer,  420;  ramming,  pav- 
ing, tamping,  420;  drives  away  chips, 
cools  cutter,  lifts  water,  421;  works 
pumps;  for  painting,  422,  423;  for 
cleansing,  423;  sandblast,  424,  425;  air 
compressors,  424-427;  inter-  ana  outer- 
cooler,  426;  heaters  for,  426;  in  quar- 
rying, 427;  Westinghouse  brakes  and 
signals,  428;  for  transmitting  power, 
348. 

Compression  in  building,  8;  members 
must  be  of  rigid  material,  19. 

Compressors,  air,   424-427;    Parsons',   372. 

Conch-shells  as  pitchers,    108. 

Concrete  and  its  reinforcement,  429-445; 
vast  uses  concrete,  431;  bridge  at  St. 
Denis;  desirable  qualities,  431;  silos, 
43i.  432;  residence,  Fort  Thomas,  Ky., 
432  and  facing  432;  for  small,  cheap 
dwellings,  432;  blocks,  general  manu- 
facture, 433,  434|  reinforcement  in- 
troduced by  Monier,  435;  bars  for, 
436,  437;  Monier  netting;  expanded 
metal.  437.  438;  molds,  438;  Pugh 
Building,  Cincinnati,  grain  elevators, 
bins,  439;  chimneys,  incorrodibility, 
440,  441;  tanks,  reservoirs,  441,  442; 
Coignet  netting,  442;  conduit,  water- 
pipes,  442;  culvert,  N.  Y.  Subway, 
443;  bridges,  443-445;  strengthened  by 


492 


INDEX 


crushed  stone,  240;  "Concrete  Con- 
struction about  <he  Home  and  on  the 
Farm,''  431,  foot-note. 

Condensers,  steam  engines,  87;  Weigh- 
ton's,  452. 

Conduit,  reinforced  concrete,  442. 

Conesp  similar,  vary  in  contents  as  cube 
of  like  dimensions,  376. 

Confectioners'  ornaments,  325. 

Contents,   solid,   ascertained,    343,   344. 

Continuous  girder  bridge,  32,  34. 

Contours  as  decided  by  material,   in. 

Contraction  withstood,  88. 

Contraries,  profit  in,  379. 

Convenience  in  machines,   106. 

Converse  inventions,  70. 

Conveyors,  69. 

Cook,  O.  F.,  on  interest  as  prime  factor 
in  discovery,  306. 

Cooking  bpx,  Norwegian,  189. 

Co-ordination,  brain,  257;  machinery,  re- 
search, in  armies,  194. 

Copernicus  as  discoverer,  270,  359. 

Copper  in  electric  bath,  103;  reduced  in 
electrical  conductivity  by  admixtures, 
175;  for  boilers,  affected  by  union 
with  antimony,  arsenic,  bismuth,  176. 

Corals  fed,   123. 

Corona  observed,  293. 

Corrodibility,  slight,  of  Jena  glass,  183; 
of  steel  reduced,  167;  of  steel  in  con- 
crete, 441. 

Corrugated  boiler,  fire-boxes,  88. 

Cotton  seed  utilized,   149. 

Counterbalance,  hydraulic  pressure,  371. 

Cowpox  prevents  smallpox,  295. 

Cram,  Ralph  Adams,  on  Japanese  wood- 
work, 113;  "Japanese  Architecture," 
114,  foot-note. 

Graver,  Harrison  W.,  Carnegie  Library, 
Pittsburg,  486. 

Crookes,  Sir  W.,  on  precise  measure- 
ment, 214;  tube,  198;  radiometer  modi- 
fied by  Nichols,  226. 

Cross-fertilization  of  sciences,  Maxwell. 
275. 

Cross-ties  introduced  on  railroads,  13; 
steel,  Pittsburg,  17. 

Croton  Dam,  concrete,  431. 

Crow  gets  at  clam,  369. 

Crystal,  alum,  broken  and  repaired,   193, 

Crystallization     iron     and     steel,     J.     W. 

Mellor,      177. 

Cube     subdivided,     121,     122;     root     ex- 
tractor, 375,  376. 
Cubit,  origin,  209. 
Culvert,   reinforced  concrete,  443. 
Cunard    steamers,    new,    128;    driven    by 

turbines,  456. 
Curie,  Pierre,  and  wife,  discover  radium, 

199. 

Curves  replace  angles,  48-51. 
Gushing,    F.    H.,   on   Zuni   water   vessels, 

108. 

Cutters,   lathe,   90;   milling,   98,    100,    101. 
Cylinder,     hollow,     for     piping,     45,     for 

boilers,     46;     strength     of,     in    organic 

forms,  250,  251. 
Cypress,  deciduous,  247,  248. 


Dacotah  fire-drill,  94. 

Daguerre's     discovery     of     photography, 
304,  305. 


Dam  in  arched  form,  45;  across  Bear 
Valley,  44. 

Darwin,  Charles,  as  observer,  280;  as 
questioner,  356;  facts  and  arguments, 
359;  on  directive  worth  of  theory, 
356. 

Davenport,  C.  B.,  experimental  evolu- 
tion, 276. 

Da  Vinci,  Leonardo,  artist  and  in- 
ventor, 308;  suspended  wheel,  382. 

Dawson,  Bernard,  open  hearth  furnace, 
164,  165. 

Dayton,  Ohio,  as  center  interurban  elec- 
tric lines,  482. 

Deck  bridge,  24. 

De  Laval,  steam  turbine,  452,  453. 

Delta  metal,  Alex.  Dick,  325. 

Dentists  first  to  use  air  tools,  419. 

De  Rochas,  Beau,  gas  engine,  462. 

Detachable  parts  of  tools  and  so  on,  239. 

De  Vries,  Hugo,  discovers  evolution  by 
leaps,  276. 

Dewar,  James,  non-conducting  glass  ves- 
sels, 375;  produces  vacuum,  327. 

Dewey,  Melvil,  decimal  classification  lit- 
erature, 352. 

Dexter   feeding  mechanism,    331. 

Diamond,  combustibility  of,  357;  arti- 
ficial, H.  Moissan,  265;  drills,  92;  sep- 
arated from  other  stones,  150. 

Dick,  Alex.,  inventor  Delta  metal,  325. 

Dies,  steel,   175. 

Diesel  oil  engine,  466. 

Diffusion   of   constituents   air,    262. 

Digestion,  impaired,  treated  with  lining 
of  ostrich  stomach,  295. 

Digit  as  measure,  209. 

Directive  paths,  332. 

Directness  as  an  aim  in  design,  342. 

Directory  iron  and  steel  works,  J.  M. 
Swank,  178. 

Discovery,  character  in,  364;  chief  im- 
pulse to,  306;  method  of,  300;  Fara- 
day on,  363,  364;  Jevons  on,  364. 

Discursiveness,    Thomas    Young,    365. 

Disease,  functional,  378;  skin,  treated 
with  Uviol  lamp,  183;  brain,  localiza- 
tion, 378. 

Dispersion  of  color,   180. 

Distribution   motive  power,    direct,   342. 

District  heating  by  steam,  448;  Lockport, 
N.  Y.,  advantages,  473;  by  water,  485. 

Division    of   labor   modified,    480. 

Dodge  &  Day  effect  economies,  244. 

Dogmatism,    Tyndall,    363. 

Dollond  lenses,   254,  255. 

Dome  built  of  arches,  355;  of  ants'  nest, 
260. 

Domestic  architecture,  new,  483. 

Douglas,  James,  on  automatic  machinery 
in  metallurgy,  332. 

Downdraft  furnace,    381. 

Dowson  producer  gas  for  lightning,  157. 

Draft,  mechanical,  380,  448,  472. 

Drama,  nature  as,  356. 

Drawing,  James  Nasmyth  on,  308. 

Dredges,  hydraulic,  259. 

Drill,  diamond,  92;  fire,  Dacotah,  94; 
steels,  418;  air,  used  as  hammer,  420. 

Drills  in  rifle-making,  282;  multiple,  290; 
ring,  91-93;  twist,  93. 

Drilling  in   lathe,   two  methods,    370. 

Drucklieb,  C.,  sandblast,  424,  425. 

Drummond,   Thomas,   lime-light,   155. 

Dry  blast  process,   Gayley,   165. 


INDEX 


493 


Dudley,   C.    B.,   anti-friction  alloys,    175. 

Dudley,  Plimmon  H.,  portrait,  facing  14; 
forms  of  rails,  14;  on  steel  for  rails, 
169. 

Dulong  and  Petit,  non-conducting  glass 
vessels,  375. 

Duncan,  R.  K.,  "The  New  Knowledge," 
204,  foot-note. 

Dundonald,  Lord,  gas  flame,  280;  down- 
draft  furnace,  381. 

Durand,  W.  F.,  on  ships  varying  in  size, 
128. 

Dust,   125;  combustible,    125. 

Dvorak  sound-mill,   132. 

Dwellings,  suggested  exhibits,  485. 

Dyes  tested  with   Uviol  lamp,   183. 

Dynamite  invented  by   Nobel,   410. 

Eads,  J.  B.,  Mississippi  jetties,  283;  St. 
Louis  bridge,  31,  41,  127. 

Ear  structure,  257. 

Karnshaw's  compensated  balance  wheel, 
223. 

Earth,  age  of,  356;  sculpture,  122. 

Eclipses,  Chaldeans  observed,  229. 

Economizer,   steam  engine,   449. 

Economy,  aim  in  invention,  341;  tested 
by  experience,  383. 

Edison,  portrait,  facing  374;  as  an  or- 
ganizer, 414;  bamboo  filament,  140; 
incandescent  lamp,  158;  on  concrete  for 
cheap  dwellings,  432;  separates  iron 
from  sand,  150;  storage  cell.  374; 
store-house,  153;  tells  how  he  in- 
vented phonograph,  310;  latest  phono- 
graph, 312. 

Education  of  eyes,  ears  and  hands,  300. 

Eel,  electric,   257. 

Egyptian  architecture,  114. 

Elasticity   explained,    358. 

Electric  cables,  X-rays  examine,  327; 
conductors  and  non-conductors,  202; 
dynamo  and  its  converse,  the  motor, 
373;  eel,  257;  heat  for  cooking,  188; 
neat,  why  too  dear  for  ordinary  warming, 
484;  heater,  Gold's,  87;  lamps  in  can- 
dle shapes,  117;  lighting,  158-162; 
lighting,  General  Electric  Co.'s  re- 
searches, 416;  lighting  current  econo- 
mized by  uniform  voltage,  243;  loco- 
motive, General  Electric  Co.,  128.  129, 
415.  476,  facing  476;  motor  aids  handi- 
craftsmen, 481;  traction,  476;  inter- 
urban,  482. 

Electrical  advances,  Lord  Rayleigh  on, 
274;  conductor,  copper  as,  affected  by 
admixtures,  175;  conductor,  iron  as, 
173;  contact,  imperfect,  leads  to  in- 
vention of  microphone  and  coherer, 
146;  experiments,  Faraday's  simple, 
391;  reversibility,  373;  sparks  useful, 
147;  Testing  Laboratories,  N.  Y.,  242; 
thermometry,  225,  226;  units  adopted, 
239. 

Electricity  for  all  possible  services,  474; 
in  the  household,  484;  for  power 
transmission,  348;  may  be  produced 
by  food,  264;  measured,  230-234; 
measures  heat,  373;  modifies  proper- 
ties, 140;  brings  new  -properties  into 
view,  197;  used  as  produced,  346. 

Electrolysis  and  its  converse,  373,  374. 

Electro-magnetism  discovered  by  Oer- 
sted, 230,  290,  373. 

Electro-magnets  curved,  50;  alloy  for,  173. 


Electro-plating  and  its  converse,  374. 

Electrons,  Joseph  J.  Thomson  on,  132; 
form  cathode  rays,  and  parts  of 
atoms,  198. 

Elements  of  chemist  probably  a  single 
substance,  357. 

Elevator  cages,  40;  grain,  68;  reinforced 
concrete,  439. 

Elliptical   hand-hole  plates,  46. 

Embossing  machines  curved,   50. 

Embroidery  machine,   319. 

Emery  testing  apparatus,   242. 

Emery  wheels,   101,   102. 

Energy,  molecule  as  reservoir  of,  131; 
potential,  358. 

Engineering  problems,  Osborne  Rey- 
nolds on,  274;  principles  in  vegeta- 
tion, 247. 

Entrance  of  ships,  53. 

Ericsson,  John,  inventive  from  child- 
hood, 303;  Life,  98;  Monitor,  97,  98. 

Erie  City  boiler,  46. 

Eskimo  ingenuity,  106;  pelts  and  bird- 
skins,  138;  skin  scraper,  91. 

Esthetic  design  of  bridges,  D.  A.  Moli- 
tor,  38. 

Ether  may  give  birth  to  matter,  358. 

Ethnology,  Bureau  of,  reports,  107,  foot- 
note. 

Everett,  Harold  A.,  acknowledgment  to, 
64. 

Evolution  proved  by  Darwin  and  Wal- 
lace, 267;  chemical  elements,  and  of 
stars,  204;  the  master  key,  357;  ex- 
perimental, 276. 

Ewart  detachable  link  belting,  69. 

Exhibits   of   dwellings  suggested,   485. 

Expanded  steel,  437,  438. 

Expansion   withstood,  88. 

Experiment,  299-328;  passion  for,  Bain 
on,  304. 

Experimental  evolution,  276. 

Explanation,  the  longing  for,  355. 

Explosions,  retarded  effects,   195. 

Explosives,  utility  of,   409,  411. 

Eye  structure,  257;  and  Dollond  lenses, 
*54,  255- 

Faber  talking  machine,  343. 

Factory  system,  rise  of,  479;  checks  to,  480. 

Faculty,   identifying,   360:   knitting,   359. 

Fan  blower,  converse  or  windmill,  371; 
for  furnaces,  372;  for  pneumatic 
tubes,  373;  for  heating  and  ventilat- 
ing, 380,  472;  screw  form,  69. 

Fanning  mill,  150. 

Fansler,  Percival  E.,  acknowledgment  to, 
xxi. 

Fant,    Thomas    E.,    acknowledgment,    xxi. 

Faraday  as  an  observer,  279;  discovery 
magneto-electricity,  373;  discovery  spe- 
cific inductive  capacity,  212;  magnetic 
researches,  201;  on  discovery,  363,  364; 
on  observations  of  untrained  men,  294; 
on  radiant  matter,  204-206;  method  _  of 
working,  389;  on  experiment,  390;  sim- 
ple apparatus  for  experiment,  390; 
orderliness,  391;  imagines  lines  of 
force,  302. 

Farm  implements  should  be  simple,  340. 

Fathom,  origin,  209. 

Feathers  have  advanced  birds  in  scale  of 
life,  250;  in  arrows,  65. 

Feeding  mechanism,   Dexter,  331. 

Fellows  gear  shaper,  67. 


494 


INDEX 


Ferguson,   Mephan,  water-pipe,  45. 

Ferrite,   164. 

Ferro-titanium  arc-lamp,    161. 

Fibre,   indurated,  322. 

Filaments  for  incandescent  lamps,  261. 

Files  sharpened  by  bubbles,   147. 

Fire    kindling,     125;    modifies    properties, 

140;  brings  properties  into  view,   197. 
Fire-arms  rifled,  65. 
Fire-boxes,    Morison   corrugated,   88. 
Fire-drill,  Dacotah,  94. 
Fire-fly,  Cuban,  263. 
Fire-lighter,   spiral,  41,   42. 
Fire-syringe,  467. 

Fischer,    L.    A.,    acknowledgment   to,   xxi. 
Fishing-rod,  in  steel  tubing,  41. 
Flaming  arc-lamp,  160. 
Flesh  frozen  for  slicing,  326. 
Flight,  mechanical,  262. 
Flint,      aboriginal,     89;      for     tools     and 

weapons,    137;    polished    by   sand,    424; 

burnt  for  white  ware,   290. 
Flour  milling,  Hungarian,  150. 
Flywheel     encased    to    lessen    air    resist- 
ance, 67. 

Folk  observation,   294-297. 
Food,  how  chosen,  135,  136;  energy  value 

of,    264;     investigated    by    W.     O.    At- 

water,    243;     with    aid    from     Carnegie 

Institution,  277. 

Foot  measure,   origin,   209;   skeleton,   250. 
Foresight  in   invention,    265. 
Form,     5-119;     conferred,     103,     104;     in 

plastic    arts,    103;    to    lessen    resistance 

to  motion,  65-71. 
Fortifications,  curves  in,  51. 
Foster,    Sir  Michael,   on  original  research 

in  medicine,  269. 

Foundries,  iron,  list,  last  paragraph,  178. 
Foundry  practice,  modern,   Geo.   R.   Bale, 

176;  compressed  air  in,  420. 
Francis  vertical  turbine,  446. 
Franklin,     Benjamin,     bi-fqcal    spectacles, 

85,    stove,    85;    proves    lightning    to    be 

electricity,   360. 

Frauenhofer  invents  spectroscope,   284. 
Freeman-Mitford,       "Bamboo       Garden," 

quoted,  141. 
Freezing    earth   to   stop   leak,    326;    water 

expands,  375. 
Friction,    Beauchamp   Tpwers     researches, 

274;  alloys  for  minimizing,  174. 
Frost  wedges  off  stone,  123. 
Froude,   Edmund,  on  ship  resistances,  53. 
Fuels     which     serve     gas     engines     better 

than  steam  engines,  466. 
Furnace    inside    boiler,    381;    downdraft, 

381. 
Furniture     embodied     with     house,     483; 

lumber  for,  bent  and  seasoned  at  once, 
'343- 

Galileo  invents  pendulum,  222. 

Gallows-pipe,  86. 

Galton,  Francis,  on  sharp  sight  and  visual 
memory,  281. 

Galvanometer,  Maxwell's,  Kelvin's,  231. 

Gang  saws,  290. 

Garden  squirt,  371. 

Gas  exploded  by  electric  spark,  147;  from 
a  candle,  457,  458;  engines,  458,  462- 
466;  producer,  459-461;  Mond  gas,  461; 
blast  furnace,  462;  for  heat,  light  and 
power,  475;  grates  imitate  maple  or 
charcoal,  117;  lighting,  154,  155,  280, 


457;  mantle,  155-59;  producer,  Loomis, 
382;  Taylor,  460;  turbine  projected, 
415. 

Gases,  kinetic  theory  of,  357;  of  the  at- 
mosphere, Sir  W.  Ramsay,  214,  foot- 
note. 

Gasoline  engines,  468. 

Gayley  dry  blast  process,  165. 

Gearing,  67. 

Geissler  tubes,  198. 

General  Electric  Co.,  locomotive,  415, 
476,  facing  476;  researches  in  light- 
ing, 416. 

Generalization  in  discovery,  306;  Simon 
Newcomb  on  need  of,  277. 

Geological  studies  aided  by  Carnegie  In- 
stitution, 277;  Survey,  U.  S.,  coal 
testing  plant,  241,  foot-note. 

Geology,  elementary,  122,  123;  records 
of,  3775  study  of,  356. 

Geometry,   Class  in,    122. 

Germany  leads  in   original   research,   275. 

Germs  destroyed  with  Uviol  lamps,   183. 

Giffard  injectpr,  347. 

Gill,  Sir  David,  on  double  star  discovery 
and  measurement,  286. 

Girders,  10-12;  box,  39;  Hennebique 
concrete,  437. 

Glacial  action  observed,  294;  Darwin  fails 
to  observe,  280. 

Glanz-stpff,   artificial  silk,   261. 

Glass,  binocular,  81,  82;  Jena,  see  Jena; 
nickel  steel  of  equal  expansibility  with, 
when  heated,  170;  prismatic  and  ribbed, 
73,  74;  rough,  for  windows,  72;  total 
reflection,  77-82;  making,  Bessemer  pul- 
verizes materials  for,  407. 

Gledhill,  J.  M.,  on  high-speed  tool  steels, 

172. 

Globes,  Holophane,  78-81. 

Gluttony,  Indian,  a  cause,  137. 

Glycerine  utilized,   149. 

Gold  betokened  by  a  bush,  296;  extraction 
of,  332;  solid,  diffuses  in  solid  lead, 
201;  alloyed  with  bismuth  has  no 
tenacity,  175. 

Gold's  electric  heater,  87. 

Goldschmidt,  Dr.,  produces  great  heat 
from  iron  oxide  and  aluminium,  145. 

Goodyear,  C.,  discovers  vulcanization  of 
rubber,  289. 

Gothic  cathedrals,  43. 

Gouges,  carving,  90. 

Gourd  as  pitcher,  108;  derived  pottery 
forms,  109. 

Graham,  Thomas,  on  states  of  matter, 
201. 

Grain  dried  for  keeping,  137;  elevator, 
68;  separated  from  chaff,  150. 

Graphitized  carbon  filament,   158. 

Gravitation,  law  of,  Newton's  discovery, 
387.. 

Gravity  as  motor  in  mills  and  post- 
offices,  321,  322;  balanced,  148,  brings 
rain  to  valley,  245;  specific,  learned, 
344. 

Gray,  Elisha,  telautograph,  315. 

Greek  sculpture,   114. 

Gribeauval,   Gen.,    interchangeability,    238. 

Griffin,  Charles,  on  convenience  in  ma- 
chines, 106. 

Grinding  lenses,  83,  84. 

Guesses  precede  theories,  358.. 

Guillaume,  C.  E.,  invents  invar,  169; 
his  unit  of  measurement,  213. 


INDEX 


495 


Gun,    built-up,    252,    253;    breech-loading, 

379;  curved,  50;   drilled,  93. 
Gunpowder  cakes,   125. 
Guthe,   K.   E.,  steatite  fibres,  235. 

Hadfield,  R.  A.,  alloy  for  electro-mag- 
nets, 173;  manganese  steel,  171. 

Haida  squaw  mats,  116. 

Haitinger,  Ludwig,  discovers  cerium  in 
gas-mantle,  156. 

Hall,  Asaph,  discovers  two  satellites  of 
Mars,  286. 

Hall,    Charles    M.,    produces    aluminium, 

Hall,  F.  W.,  mechanical  treatment  steel 
(see  under  Harbord),  177. 

Halsey,  T.  S.,  on  premium  plans  for 
wages,  244,  foot-note. 

Hammer,  air,  419;  drill  used  as,  420; 
wasp  using  pebble  as,  260. 

Hand-breadth  as  measure,  209. 

Hand-hole  plates,  Erie  City  boiler,  46. 

Handicrafts  revived,  481. 

Handwork  should  not  be  directly  imi- 
tated in  machine  design,  342. 

Harbord,  F.  W.,  Metallurgy  of  steel,  177. 

Harcourt  lamp,  using  pentane,   226. 

Harcourt,  Rev.  Vernon,  makes  new  glass, 
181. 

Hargreaves,  James,  invents  spinning 
jenny,  290. 

Harris  compressed-air  pump,  422. 

Harris  rotary  press,  48. 

Harrow  simple,  340. 

Harvester,  self-binding,  478. 

Harvey,  discovery  movements  heart  and 
blood,  267,  272,  359. 

Haymaking  and  law  of  size,   130. 

Heart  and  built-up  gun,  252,  253. 

Heat  as  motion,  358;  conservation  of, 
250;  converted  into  work,  263;  economy, 
85,  86;  electric,  for  cooking,  188;  light 
and  motive  power  from  central  sta- 
tions, 473-374,  481;  measured  by  elec- 
tricity, 373;  nen-conductors,  186-188, 
190-  treatment  of  steel,  167;  withstood 
by  Jena  glass,  183. 

Heater,  Gold's  electric,  87. 

Heating  and  power  production  united, 
471;  ventilating,  and  Sturtevant  meth- 
ods, 380,  472;  coils,  86;  district,  by 
steam,  448,  by  water,  Morris  Building 
Co.,  Brooklyn,  485. 

Hefner  unit  of  illumination,  226. 

Helium,  density,  213;  in  sun,  in  min- 
erals, may  be  a  constituent  of  chemical 
elements,  202. 

Helmholtz  ophthalmoscope,   321. 

Herkomer,  Hubert,  direct  reproduction, 
342. 

Herschel,  resources  of,  305. 

Heusler,  F.,  magnetic  alloys  of  non- 
magnetic elements,  173. 

Hewitt  mercury-vapor  lamp,  161;  Jena 
glass  for,  183. 

Hides  prepared  for  use,  138. 

Hillman,  H.  W.,  household  uses  elec- 
tricity. 484. 

Hip  joint  section,   252. 

Holloway,  J.  F.,  supports  turbine  by  up- 
ward pressure  water,  371. 

Holmes,  W.  H.,  Art  in  shell  of  the  An- 
cient Americans,  116;  form  and  or- 
nament in  ceramic  art,  in,  115;  Pot- 
tery of  the  Ancient  Pueblos,  108,  109. 


Holophane  globes,  78-81,  229. 

Homestead  blowing  machinery,  415. 

Hood,  ventilating,  for  alcohol  lamp,  158. 

iiooke's   universal  joint,    256. 

"Hopes  and  fears  for  art,  Wm.  Morris, 
quoted,  114. 

Hopkinson,  J.,  on  limits  to  rules,  383; 
on  mathematical  analysis,  384. 

Hornet  and  moth,  resemblances,  288. 

liorse,   evolution  of,   249. 

Hottentots  learn  from  baboons,  136;  an- 
tidotes for  snake  venoms,  296. 

Hough,    Walter,   acknowledgment  to,   xxi. 

Houses   numbered,    351,   352. 

Howe,  truss,  24,  25. 

Howe,  H.  M.,  "Iron,  steel  and  other  al- 
loys"; "Metallurgy  of  steel,"  177. 

Howell,  Wilson  S.,  maintains  uniform 
voltage,  243. 

Howells,  W.  D.,  "Hazard  of  new  for- 
tunes" quoted,  306. 

Hudson,   \V.    H.,   on   folk   medicine,   295. 

Hughes,  David   K.,  microphone,   147. 

Hull,  Gordon  F.,  on  pressure  of  light, 
'33- 

"Human  body,"  H.  N.   Martin,  252. 

Hungarian  milling,  321. 

Husscy,  Obed,  mower,  320. 

Hutton,  F.   R.,  on  gas  engine,  464. 

liuygens   employs  pendulum,  222. 

Hyatt  bearing,  47,  49. 

Hyde,  E.  P.,  Bureau  of  Standards,  pho- 
tometer, 235. 

Hydraulic  presses  curved,  50;  pressure  as 
counterbalance,  371. 

Hydrogen  in  thermometry,  225. 

I-beam  developed  from  joist,  10. 

Ice-lens  focusses  solar  rays,  5. 

Identifying  faculty,  360. 

Idiom  of  material,  in. 

Ignorance  and  discovery,  294;  Bessemer's 
golden,  403. 

Illumination,  Art  of,  Louis  Bell,  229, 
foot-note. 

Imagination  jn  invention,  309;  Faraday's 
powers  of,  392;  Tyndall  on,  361. 

Imitation  of  Nature,  249. 

Indian  gluttony,  a  cause  of,  137. 

Indicative  plants,  296. 

Individuality  of  matter,  358. 

Indurated  fibre,  322. 

Ingalls  Building,  Cincinnati,  concrete, 
438,  440. 

Ingersoll  coal  cutter,  418. 

Ingersoll,  Ernest,  acknowledgment  to,  xxi; 
on  debt  9f  birds  to  feathers,  250. 

Initiation  in  chemistry,  337,  in  photog- 
raphy, 338. 

Injector,  Giffard,  347. 

Inking  rollers,  40. 

Inks  tested  with  Uviol  lamp,   183. 

Insanity,  its  revelations,   379. 

Insects  trapped  by  sundew,  281. 

Instruments  aiding  observation,  356;  ad- 
vance astronomy,  230. 

Interborough  power-house,  roof  truss,  21; 
tests  coal,  241;  exterior  facing  450;  in- 
terior facing  452;  automatic  machinery, 

Interchangeability  old  and  new,  238,  239. 
Interest  as  prime  factor  in  discovery,  306. 
Interference  water-waves,  214:  light,  215, 
216,  discovered  by  Thomas  Young,  366. 
Interferometer,  214-217. 


496 


INDEX 


Introductory,  i. 

Invar,   169,  used  for  time-pieces,  223. 

Invention  at  first  slow,  115;  Bessemer  on 
nursing  and  tending  an,  407;  organ- 
ized in  America,  414,  in  Germany,  275; 
prerequisites,  271;  social  aspects  of, 
478;  literature  of,  486. 

Inventions,  origin  of,  O.  T.  Mason,  107. 

Inventors  improve  their  work  in  act  of 
construction,  300. 

Inverted  arc-light,  75,  76,  381. 

Iron,  inflammable  variety  of,  151;  crys- 
tallization, J.  W.  Mellor,  177;  as  elec- 
trical conductor,  as  affected  by  admix- 
tures, 173;  its  three  forms,  151;  foun- 
dries, list,  foot  178;  history  manufac- 
ture, J.  M.  Swank,  178;  metallurgy, 
A.  H.  Sexton,  178;  T.  Turner,  179; 
works,  directory,  J.  M.  Swank,  178; 
steel  and  other  alloys,  H.  M.  Howe, 
177;  strength  of  wrought,  20,  21;  and 
steel  manufacture,  H.  H.  Campbell, 
177;  Sir  I.  L.  Bell,  177;  Institute 
Journal,  179. 

Isolated  plants,  473-74;  serving  neigh- 
borhood, 475,  481. 

Jackson,  Robert  T.,  observation  leaves, 
281. 

James,  William,  on  discovery,  359;  on 
limits  to  rules,  382. 

Japanese  architecture,  Ralph  Adams 
Cram,  114,  foot-note;  pottery,  113, 
288;  wood-work,  113. 

Jena  glass,  180;  first  experiments,  181; 
refraction  and  dispersion,  181;  trans- 
parent, 182;  in  photography,  182,  183; 
in  microscopy,  182;  annealing,  182-  in 
thermometry,  182,  225;  resists  heat 
and  corrosion,  183;  transmits  ultra- 
violet rays,  183;  lenses,  255. 

Tenner,  Dr.,  vaccination,  295. 

Jetties,  Mississippi,  J.   B.   Eads,   283. 

Jevons,  W.  S.,  "Principles  of  Science," 
229;  on  discovery,  364. 

Joint,  Hooke's  universal,  25$. 

Joist  more  rigid  than  plank,  7;  and  plank 
bent  double,  7. 

Joule,  J.  P.,  discovery  of  thermo-dynamic 
law,  212. 

Journal  Iron  and  Steel  Institute,   179. 

Journals,  hollow,  40. 

Judgment,  William  James  on,  382;  Alex. 
Bain  on,  385;  moves  to  new  fields, 
385;  in  ship  design,  63. 

Jupiter,  size  of,  121;  fifth  satellite  discov- 
ered by  E.  E.  Barnard,  285. 

Justifying  wedges,   323-325. 

Kaiser  Wilhelm  II.,  steamer,   59,   60. 

Kelp  absorbs  from  sea  iodine  and  bro- 
mine, 296. 

Kelvin,  Lord,  estimates  size  molecule, 
131;  defines  entrance  and  run  of 
ships,  53;  on  measurement,  211. 

Kennedy,  A.  B.  W.,  on  simplification, 
341;  on  economy  in  machines,  383. 

Kepler  as  discoverer,  270,  305;  his  law, 
388. 

Kersten,  Frederick,  separates  diamonds 
from  other  stones,  150. 

Kidneys,  disease  of,  affects  vision,  379. 

Kingpost  truss,   18. 

Kites    improved   by   perforation,    292. 

Knitting  faculty,  359. 


Knives,  90. 

Knowledge  necessary  to  inventor  and  dis- 
coverer, 267;   Bessemer's  view,  408. 
Koebele,   Albert,   saves  orange  groves,  282. 
Krakatoa  volcano   125. 
Krypton,   213. 
Kuzel,  Hans,  tungsten  electric  lamp,   160. 

Labor,  division  of,  modified,  480;  saving 
deyices  in  farming,  478. 

Lachine  bridge,  32. 

Lalance  &  Grosjean,  pressed  ware,   185. 

Lamp  and  reflector  a  unit,  75;  giving 
heat  and  light,  343;  arc,  160;  incandes- 
cent, as  standard,  227. 

Langley,  S.  P.,  bolometer,  225;  churns 
air  in  telescope,  348;  mechanical  flight, 
262;  on  Cuban  firefly,  263. 

Larned,  J.  N.,  editor  Literature  of 
American  History,"  xxii. 

Lathe,  95-98;  cutters,  90;  rotary  man- 
drel, 48;  tool,  93,  94. 

Lattice  trusses,  where  best,  35;  showing 
rivets,  36. 

Lavoisier  balance,  209. 

Law  as  binding  thread,  134. 

Lead,  solid,  dissolves  solid  gold,  201; 
pipe  made  by  pressure,  325. 

Leaves  observed  by  R.  T.  Jackson,  281. 

Le  Chatelier,  electrical  thermometer,  226. 

Lenard,  Philipp,  cathode  rays,   198. 

Lenoir  gas  engine,  458. 

Lens,  Dollond,  254,  255;  Fresnel,  72,  74; 
grinding,  83,  84. 

Le  Vaillant  on  food  eaten  by  monkeys, 
259. 

Leverrier,  Urbain,  discovers  Neptune, 
378. 

Levers  and  limbs,  256. 

Libraries,  public,  technological  depart- 
ments, 486-87. 

Light  causes  sound,  393;  398-400;  colors 
investigated  by  spectrometer,  228;  de- 
flects dust,  133;  explodes  a  compound, 
337;  interference  of,  215,  216;  discov- 
ered by  Young,  366;  measurement  of, 
226,  228;  polarized,  reveals  strains, 
rock  structure,  measures  sugar,  327; 
pressure  of,  133;  reflection,  229,  total, 
76-82;  sources  of,  154;  ultra-violet, 
Jena  glass  utilizes,  182;  violet  and  yel- 
low, photographic  effects,  338;  well 
transmitted  by  Jena  glass,  182;  what 
it  should  cost  in  mechanical  energy, 
158;  arc,  inverted,  75,  76,  381;  Drum- 
mond  lime,  155;  wave  as  unit  of 
length,  217. 

Lighthouse,  curves  for  base,  51;  fcas 
form  of  tree,  250; 

Lighting,  electric,  158-162;  General  Elec- 
tric Co.'s  researches,  416. 

Lightning  paths,  245;  protection  through 
warm  air  and  smoke,  294. 

Lime-light,   Drummond,   155. 

Limits  to  rules,  382. 

Link  Belt  Machinery  Co.'s  Shop,  Chi- 
cago, 380. 

Link  belting,  69. 

Linotype,  Mergenthaler,  323. 

Literature  of  invention  and  discovery, 
486. 

Lithography,  aluminium  for,  144. 

Liver  as  sugar-maker,  262. 

Lobster's  tail,  hint  from,  259. 

Lock-woven  wire  fabric,  439. 


INDEX 


497 


Locking  bar  water-pipe,   Ferguson,  45. 

Lockyer,  Sir  Norman,  on  stellar  evolu- 
tion, 204. 

Locomotive  with  cog  wheels,  345,  346;  gas 
engine  for,  466;  high  pressure  steam 
for,  studied  with  aid  from  Carnegie  In- 
stitution, 277;  increased  in  weight,  15; 
tests,  Pennsylvania  R.  R.  Co.,  241. 
foot-note;  with  and  without  super- 
heaters, 451;  General  Electric  Co.,  128, 
129,  415,  476,  facing  476. 

Lodge,  Sir  Oliver  J.,  on  bad  electrical 
contact,  146. 

Looms,  Nortnrup,  330. 

Lubricating  oil  reservoirs,  447. 

Lumber,  how  dried,  130;  for  furniture 
bent  and  seasoned  at  once,  343. 

Lungs,  separation  of  oxygen  from  air  by, 
261. 

"Lusitania,"   steamer,    128. 

Luxfer  prism,   74. 

Mach,  Ernst,  on  accidental  discovery, 
291. 

Machine  tools,  94-101. 

Machines  code  their  operations,  317. 

Madison   Square  Garden  curve,   50. 

Magazine-rifle  tubes,  40. 

Magnet  in  steel-making,    168;  curved,   50. 

Magnets  in  astatic  needle,   149. 

Magnetism  measured,  Bureau  of  Stand- 
ards, 235. 

Magnetite  arc-lamp,   161. 

Magnetization  leaves  traces,  192;  J.  Hop- 
kmson  on,  384. 

Magneto-electricity  discovered  by  Fara- 
day, 373. 

Malaria  and  mosquitos,   295. 

Mandolin   pressed  in  aluminium,    185. 

Manganese  steel,  non-magnetic  and  tough, 
171. 

Manganin,  Weston's,  234. 

Mangle  rolls,  40. 

Mangling  and  drying  at  once,  343. 

Mann,   C.   R.,  acknowledgment  to,  xxi. 

Mantle,  gas,  Welsbach,  155-59. 

Manual  training,  309,  310. 

Manufacturing,  tendencies  in,  E.  Atkin- 
son, 480,  foot-note. 

Marble  is  plastic,  152;  deformed  by  pres- 
sure, 195,  196. 

Mars  satellites  discovered  by  Asaph  Hall, 
286. 

Martin,  H.  N.,  "Human  Body,"  252. 

Mason,  Otis  T.,  "Basket  work  of  N.  A. 
aborigines,"  112;  "Indian  Basketry," 
foot-note,  no,  142;  on  British  Colum- 
bian basketry,  no;  on  Pai  Utes'  water- 
bottles,  in;  "Origin  of  inventions." 
"Woman's  share  in  primitive  culture," 
107. 

Material,  idiom  of,   in. 

Mathematical  analysis,  J.  Hopkinson  on, 
384. 

Matter,  constitution  of,  358;  impressed 
by  its  history,  190. 

Maudslay  as  a  mechanic,  299;  as  a 
trainer  of  other  inventors,  300;  sense 
of  form,  308;  slide-rest,  94,  96. 

"Mauretania,"  steamer,   128. 

Maxwell,  James  Clerk,  on  Faraday's  lines 
of_  force,  392;  on  cross-fertilization  of 
sciences,  275. 

Mayer,  A.  M.,  magnetic  experiments,  192, 
193. 


Measurement,  208-244;  discussed  by  A.  B. 

W.   Kennedy,  383;   its  beginnings,  208; 

irregular  areas,   347;   light-wave  as  unit 

of,     217;      refraction,     344;     standards 

sought,  210. 

Mechanical  draft,  380,  448,  472. 
Medicine,    original    research   in,    269,   272, 

273. 
Mellor,   J.    W.,    "Crystallization   iron  and 

steel,"   178. 
Memorial     Bridge,     Washington,     D.     C., 

Memory  for  observations,  293. 

Mendenhall,  T.  C.,  designs  pendulum, 
224. 

Mercer,  John,  and  mercerization,  138. 

Mercury  thermometer,  225;  vapor  lamp, 
Hewitt,  161. 

Mergenthaler  linotype,  323. 

Metal  pressing,   Bliss,    184-186. 

Metallography,  study  of,  J.  W.  Mellor, 
'77- 

Metallurgical  machinery,  automatic,  332. 

Metallurgie,   Revue  de,   179. 

Metcalf,  Wm.,  axe  and  its  story,  377. 

Meteorology,  338,  339. 

Metre,  origin,  210. 

Metric  system,   210,  211. 

Michelson,  A.  A.,  portrait,  facing  214; 
interferometer,  214-217. 

Micrometer  caliper,  236. 

Microphone,  origin  of,    147. 

Microscopy,   Tena  glass  for,    182. 

Mile,  nautical,  211. 

Mill,  John  Stuart,  four  methods  experi- 
mental inquiry,  360;  on  sound  observa- 
tion, 279. 

Miller,  Hugh,  "My  schools  and  school- 
masters" quoted,  307. 

Milling  cutters,  48,  98,  100,  101;  tell 
story,  377;  machine,  98,  100,  likely  to 
gain  on  planer,  173,  cuts  gears,  67. 

Mining  in  Hartz  mountains,  411;  placer, 
124;  separations  in,  126. 

Mississippi  mud,   123;  jetties,  J.  B.   Kads, 


itch' 
xxi. 


ftchell, 


Mite 


Walter  A.,  acknowledgment  to, 


Models  and  law  of  size,   126,  127. 
Modernizing  a  plant,  243. 
Moissan,   Henri,   artificial   diamonds.   265. 
Moisture    necessary    for    combustion     in 

™°iX7gen'  i338'  374> 
Molding  clay,   102,   103. 

Molds,   reinforced  concrete,  438,  440. 

Molecule,  size,  130;  as  reservoir  energy, 
131. 

Molitor,  D.  A.,  esthetic  design  of  bridges, 
38,  foot-note. 

Molybdenum  in  high-speed  tool  steel,  172. 

Mond  gas,  461. 

Monier,  Joseph,  reinforces  concrete,  435; 
netting,  437. 

Monitor,  Ericsson's,  97,  98. 

Montreal,  Notre  Dame  de  Bonsecours,  118. 

Moon,  size  of,  121;  motions  observed  by 
Chaldeans,  293. 

Moor  grass,  section,  251. 

Morris  Building  Co.,  Brooklyn,  hot- 
water  service,  48  5. 

Morris,  William,  ''Hopes  and  fears  for 
art"  quoted,  114. 

Morse,  Edward  S.,  naturalist,  archaeolo- 
gical observer,  287,  288;  on  Japanese 
pottery,  113. 


498 


INDEX 


Morse  signals  on  Burke  system,  354. 

Mortar,   Roman,    139. 

Mosquitos  and  malaria,  295. 

Moth  and  hornet,   resemblances,   288. 

Motion  may  explain  properties,   207. 

Motive  power  produced  with  new  econ- 
omy, 446-477;  of  human  body,  250. 

Mpulton,  Sir  John  Fletcher,  on  coding 
in  invention,  317. 

Mower,  Obed  Hussey,  320. 

Multiple  drills,  saws,  punches,   290. 

Murdock,  Wm.,  introduces  gas-lighting, 
154,  280. 

Murphy  machine  shears  timber,  322. 

Muscles,  fibrils  of,  258. 

Mushet,  R.  F.,  high-speed  tool  steel,   171. 

Musical  instruments  and  their  prototypes, 
257- 

Narwhal  tusk,  259. 

Nasmyth,  Alexander,  invented  bow  string 
bridge,  308. 

Nasmyth,  James,  trained  by  Maudslay, 
300;  on  drawing,  308. 

National  Museum,  Washington,  aborig- 
inal art,  1 06. 

Nature  a  drama,  not  a  tableau,  355;  as 
teacher,  245-266;  unity  of,  357. 

Nebular  theory  illustrated,    149. 

Needle  for  sewing-machine,  379. 

Neon,  213. 

Neptune,  discovery  of,  214,  378. 

Newark  Public  Library,  487. 

Newcomb,  Simon,  on  original  research, 
269;  on  analysis  and  generalization, 
277. 

Newton  as  a  boy  tireless  in  construc- 
tion, 301;  makes  a  sundial  and  a  tele- 
scope, measures  force  of  storm,  302; 
corpuscular  theory  of  light,  203;  dis- 
covery of  law  of  gravitation,  211,  387; 
fails  to  observe  black  lines  of  solar 
spectrum,  284;  on  achromatism,  254; 
rings,  237,  238. 

New  Amsterdam  Theater,  New  York, 
119,  facing  1 1 8. 

New  York  Central  R.  R.  Line,  its 
course,  246. 

New    York    Subway,    reinforced   concrete, 

Niagara  Falls  retiring,  123;  turbines  at, 
70,  371. 

Nichols,  Ernest  F.,  on  pressure  of  light, 
133;  sensitive  thermometer,  226. 

Nickel,   how  made  malleable,    176. 

Nickel-steel,  166,  167;  of  like  expansi- 
bility with  glass  when  heated,  170; 
which  shrinks  when  heated,  170. 

Nickelin,   Weston's,   234. 

Nicolaysen,   N.,  on  Viking  ship,   57. 

Nitro-glycerine,  409,  410. 

Nobel,  Alfred,  improves  nitro-glycerine, 
410,  invents  dynamite,  410;  profits  by 
accidental  use  of  collodion,  411;  in- 
vents smokeless  powder,  412;  charac- 
ter and  benefactions,  413. 

Noise  desirable  as  warning,    148. 

Non-conductors    heat,    186-188,    190,    374, 

Northrop  looms,  330. 

Norton,  Prof.  C.  L.,  on  window  glass,  73; 

on  corrosion  steel  in  concrete,  441. 
Notre    Dame    de    Bonsecours,    Montreal, 

118. 
Norwegian  cooking  box,  189,  374. 


Notes,  cards  for,  350. 

Numbering  houses  and  rooms,  351,  352. 

Observation,  279-298;  a  matter  of  mind 
as  well  as  of  eye,  279;  now  fuller  than 
formerly,  152;  Kersten's  leads  to 
mechanical  separation  of  diamonds 
from  other  stones,  150;  Mercer's,  leads 
to  mercerization,  138. 

Odor,  distressing,  is  useful,    146. 

Oersted's  discovery  of  electro-magnetism, 
230,  290,  373. 

Office-buildings,  New  York,  115. 

Oil  engines,   466. 

Oils,  Bessemer  improves  drying  of,  409. 

Omission  gainful,  345,  346. 

Open  hearth  process,   164. 

Ophthalmoscope,    Helmholtz,    321,    379. 

Orange  groves  saved  from  fluted  scale 
insect,  281. 

Ordway,  J.  M.,  on  non-conductors  heat, 
187. 

Ore  stamps,  Edwin  Reynolds,  344. 

Organic  and  inorganic  series  united,   357. 

Organized  invention,  414. 

Origin  of  inventions,  O.  T.   Mason,   107. 

Original  research,  267-278. 

Osmium  electric  lamp,  160. 

Ostwald,  W.,  on  original  research  in 
Germany,  275. 

Otto  gas  engine,  463. 

Oven  and  its  converse,  the  safe,  374. 

Oxygen  dry  does  not  support  combus- 
tion, 374;  from  air,  261. 

Pace  as  measure,  209. 

Packages  and  wrappings,   130. 

Pai  Utes'  water  bottles,   in. 

Painting  by  immersion,  348;  compressed 
air  for,  422,  423. 

Paley  on  proof,  359. 

Palladio  trusses,  22. 

Panel  of  bridge,  23. 

Paper  in  continuous  rolls,  346;  from 
wood  suggested  by  wasp  nest,  261; 
making,  322;  steam  cylinders  in  343; 
toughened,  139;  white,  as  reflector,  76. 

Paraffin  e  is  plastic,  195. 

Parchment,  vegetable,   139. 

Parsons,  Charles  A.,  air  compressor,  372; 
steam  turbine,  453-456,  performances, 
455,  on  "Turbima"  and  other  vessels, 
455,  456. 

Pascal,  powers  of,  270. 

Pasteur's  researches,   273. 

Paths  of  least  resistance,  245;  directive, 
332. 

Paunch  copied  in  pottery,   115,  116. 

Pavements,   concrete,   430. 

Peabody,  Cecil  H.,  on  ship  models,  54. 

Pearlite,   164,  facing  164. 

Pearson,   Karl,    on   original   research,   277^. 

Pease,  Edson  L.,  acknowledgment  to,  xxi. 

Peck,  Ashley  P.,  acknowledgment  to,  xxi. 

Peckham,  G.  W.  and  E.  G.,  "Wasps 
solitary  and  social,"  260. 

Pelton  wheel,  71,  332. 

Pendulum,  222;  invar  for,  170;  compen- 
sating, 148;  measures  gravity,  224. 

Pennsylvania  R.  R.  Co.,  testing  labora- 
tory; "Locomotive  tests  and  exhibits," 
241. 

Pentane  in  thermometry,  225;  in  Har- 
court  lamp,  226. 

Pepsine,  295. 


INDEX 


499 


Perch,  Sacramento,  totally  reflected  in 
tank,  77. 

Perforated  sails  for  ships,  291. 

Phonograph,  how  Edison  invented,  310; 
its  latest  form,  312;  its  directness,  343; 
sapphire  for  stylus,  153. 

Phosphorescence,  152;  a  phase  of  radio- 
activity, 199. 

Photographic  action  of  radio-active  sub- 
stances, 199. 

Photography,  Wollaston  on  threshold  of, 
284;  discovery  of,  Daguerre,  304,  305; 
aids  astronomer,  356;  effects  viplet  and 
yellow  rays,  338;  Tena  glass  in,  182, 
183;  reproduces  books,  324;  silver 
compounds,  152. 

Photometer,  Bunsen's,  227;  Matthews', 
228;  Hyde's,  235;  Faraday's  simple,  391. 

Phrenology  absurd,  359. 

Pianola,  333-335- 

Pianos  shipped  in  refrigerator  cars,  349. 

Picard  measures  the  earth,  388. 

Pickering,  E.  C.,  on  astronomical  co- 
operation, 278. 

Picturing    power,    307,    309. 

Piling,   reinforced  concrete,   438. 

Pin-connected  trusses,  where  best,  35; 
bridges,  36,  37. 

Pine  tree  growing  by  itself,   248. 

Pipe,  gallows,  86;  grass,  section,  251. 

Pitchblende,  a  source  of  radium,  199. 

Pitcher,  pressed  seamless,   185. 

Placer  mining,  124. 

Planers,  97,  98,  99. 

Planets  differ  in  size,  120. 

Planimeter,  347. 

Plants,  indicative,  296. 

Plaster  ornaments,  how  made,  325. 

Plastic  arts,  form  in,  103. 

Plate  girders,  where  best,  35. 

Plateau's  experiment,   148. 

Platinum  as  lamp  filament,  158. 

Plauen,  Germany,  bridge,  42,  43. 

Plow,  its  beginnings,  380;  works  well  be- 
cause simple,  340. 

Plowshare  improved,  91;  of  two  kinds  of 
steel,  167;  self -sharpening,  258;  re- 
movable, 239. 

Plucker  tubes,  198. 

Plug  and  ring,  237. 

Pneumatic  hammer  in  steel  tubing,  41; 
tools,  40,  41;  tube  cleared,  321. 

Poetsch,  H.,  freezes  sand  to  stop  influx 
water,  326. 

Polarized  light  reveals  strains,  rock  struc- 
ture, measures  sugar,  327. 

Pomo  basket,  109. 

Porro  prisms  81,  82. 

Portland  cement,  430. 

Post  of  bridge,  23. 

Post  office  and  branches,  256;  Chicago, 
gravity  as  motor  In,  322. 

Potential  energy,  358. 

Potter,  Humphrey,  invents  self-acting 
valve-motion,  329. 

Pottery  forms,  112;  Japanese,  IT 7,  288; 
of  the  Ancient  Pueblos,  W.  H.  Holmes, 
1 08,  100;  origin  of  white  ware,  290. 

Poulsen,  Valdemar,  telegraphone,  313. 

Powder.  Nobel's  smokeless.  412. 

Pratt  Institute  Library,  Brooklyn,  487. 

Pratt  truss,  24,  25. 

Premium  plans  of  wages,   244. 

Press,  perfecting.  48;  Bliss,  work,  184- 
186;  forming  die,  184. 


Pressing,    103,    184-186. 

Pressure,  extreme,  its  effects,  152;  shap- 
ing plaster,  soap,  clay,  lead,  325. 

Priestley  on  observation,  293. 

Primrose,  mutations  of,  276. 

"Principles  of  Science."  W.  S.  Jevons, 
229. 

Prism,  Porro,  81,  82;  total  reflection,  77, 
78,  8 1,  82. 

Prismatic  glass,  73,  74. 

Producer  gas,  459;  advantageous,  F.  W. 
Harbord,  476;  Dowson,  for  lighting, 

1$7< 

Projectiles,  forms,  65. 

Proof  of  theories,  358. 

Propeller,  69;  improved  by  accidental 
break,  291. 

Properties,  135-207;  all,  probably  exist  in 
all  matter,  152,  190,  202,  393;  may  be 
due  to  motion,  207,  357;  modified,  137; 
produced  as  needed,  152;  family  ties, 
1 88;  Faraday  on  changes  in,  206;  may 
change  in  time,  195;  vary  in  effect  with 
rapid  or  slow  action,  195. 

Protective  resemblances,   288. 

Providence   Public    Library,   487. 

Prowse,  Geo.  R.,  acknowledgment  to,  xxi. 

Ptolemy,  observations,  229;  astrolabe,  230. 

Public  libraries,  technological  depart- 
ments, 486. 

Pugh  Power  Building,  Cincinnati,  con- 
crete, 439. 

Pump  resembles  garden  squirt,  371; 
screw,  Edwin  Reynolds.  70;  compressed 
air  for,  421,  422;  Worthington,  70,  371. 

Punches,  multiple,  290. 

Pupin,  Michael  I.,  telephonic  researches, 
366-369. 

Puzzuoli  ashes  for  hydraulic  cement,  429. 

Pye-Smith,  Dr.,  on  knowledge,  267;  on 
disinterested  quests,  272;  on  verifica- 
tion, 358. 

Quantitative  inquiry,  209. 
Quarrying,  compressed  air  in,  427. 
Queen-post   truss,    21;    two,   trusses   form 
a  bridge,  22. 

Radiation  may  be  material  or  ethereal, 
203. 

Radiator  tubing,  87. 

Radio-activity,  197-207;  and  alchemy,  203; 
may  explain  heat  of  earth  and  sun, 
evolution  of  chemical  elements,  204; 
compared  with  common  evaporation, 
200. 

Radium  discovered  by  Pierre  Curie  and 
wife,  199;  investigated  by  Ernest 
Rutherford,  ipo;  where  found,  200; 
heat  of,  probable  life,  fund  of  energy, 
202;  warmer  than  surroundings,  132. 

Railroad,  best  lines  for,  246;  bridges,  23; 
carriages,  European,  118,  342;  cross- 
ings, frogs,  switches  of  manganese 
steel,  171;  economies  due  to  improved 
rails,  15;  engineers  observe  buffalo 
trails,  259;  Russian,  247;  track  cleared 
by  steam,  124,  dipping  downward,  66, 
67;  trains,  fast,  Zossen,  66. 

Rails  for  railroads,  13;  Dudleys  forms, 
16;  steel  for,  169. 

Raiment,    how   chosen,    13*. 

Rammer,   compressed  air  for  420. 

Ramsay,  Sir  William,  "Gases  of  the 
atmosphere,"  214,  foot-note. 


500 


INDEX 


Range,  steel,  pressed,  185,  186. 

Ransome,  E.  L.,  designer  in  reinforced 
concrete,  436,  439. 

Ratchet  bit  brace,  90. 

Rayleigh,  Lord,  discovers  argon,  213; 
on  electrical  advances,  274;  theory  of 
sound,  366. 

Raymond,  R.  W.,  on  indicative  plants, 
296. 

Reaping  machine,  Obed  Hussey,  320; 
must  be  carefully  used,  341. 

Reeds,   Egyptian,  as  drills,  93. 

Reflection,  75,  76;  total,  76-82. 

Refraction  measured,  344. 

Refrigerator  cars  for  shipping  pianos,  349. 

Reinforced  concrete.     See  Concrete. 

Removable  parts  of  tools,  239. 

Research,   original,  267-278. 

Resemblances,  protective,  288. 

Reservoir,  reinforced  concrete,  442. 

Residual  phenomena,  214. 

Resistance  ships,  52,  53,  277;  canal  boat, 
282. 

Resources,  material,  as  affecting  inven- 
tion, 1 06. 

Responsiveness  in   plants,   248. 

Reuleaux,  F.,  pn  seamless  boilers,  46; 
on  minimum  number  parts  in  ma- 
chine, 341. 

Reversibility,   electrical,   373. 

Revue  de  Metallurgle,   179. 

Reymond,  Dubois,  investigates  muscle 
and  nerve,  272. 

Reynolds,  Edwin,  screw  pump,  70;  ore- 
stamps,  344. 

Reynolds,  Osborne,  on  engineering  prob- 
lems, 274. 

Rheostat,  316. 

Ribbed  glass,   73,   74. 

Rice,  H.  H.,  on  concrete  blocks,  433-435. 

Rifle-making,  tendency  of  drills,   282. 

Rifling  of  fire-arms,   65. 

Rigidity  due  to  motion,  358. 

Riley,  C.  V.,  saves  orange  groves,  281. 

Ring  drills,  91-93. 

Riveting  in  bridges,  36,  37;  machine, 
Fairbairn,  370. 

Roads,  best  lines  for,  246;  Roman,  410. 

Roberts-Austen,  experiments  with  alloys, 
preparing  steel  dies,  175;  interpene- 
tration  of  metals,  201. 

Robins  conveying  belt,  68. 

Rock  structure,  polarized  light  reveals, 
327;  dissolved  with  acid.  347. 

Roller   bearings,    47,   49;    for   bridges,   38. 

Rolls  for  steel,   104. 

Roman  cement,  429;  mortar,  139;  roads, 
410. 

Rontgen,  C.  W.,  X-rays,   108. 

Roof  truss,  Interborough  Co.,  N.  Y.,   21. 

Roofs  in  France  and  Canada,   118,  119. 

"Roosevelt,"  Arctic  ship,  19,  20. 

Rope   for  transmission   power,    347. 

Rose,  Joshua,  on  lathe  tools,  94. 

Ross,  Dr.  Donald,  proves  malaria  due  to 
mosquitos,  295. 

Rowland,  H.  A.,  fond  of  experiment 
from  childhood,  303. 

Royal  Bank  of  Canada,  Havana,  facing 
438. 

Royal  Institution,  London,  founded  by 
Count  Rumford,  365. 

Rubber  may  rebound  from  a  wall  or 
pierce  it,  196;  cylinders,  hollow  and 


solid,   40;   vulcanization,    C.    Goodyear, 

289. 

Rudders,  Chinese,  with  apertures,  292. 
Rules   have   limits,    382;    that   work   both 

ways,  369-379- 

Rumford,  Count,  founds  Royal  Institu- 
tion, 365;  proves  heat  to  be  motion, 

206. 

Run  of  ships,  53. 

Rupture  of  metal,  how  avoidable,  333. 
Rutherford,    Ernest,    portrait    facing   202; 

researches  in  radium,   199;  in  thorium; 

opinion    with    regard    to    hefium,    202; 

spontaneous    transformation    of    matter, 

203.     "Radio-activity,"  203. 

Sacramento     perch     totally     reflected     in 

tank,  77. 

Safe  ana  its  converse,  the  oven,  374. 
Sailing  vessel  forms,  55. 
Sails  perforated,  291. 
St.    Louis   bridge,    31,    41;    why  in   three 

spans,  127;  recent  architecture,  112. 
St.  Remy,  Church  of,  43. 
Salt  preserves  food,  138. 
Sampler,  114,  115. 
San    Francisco    fire,    reinforced    concrete 

in,  440. 
Sand  blast,   124,  424,  425;  polishes  flints, 

424;    sifter,    compressed    air    for,    420; 

wind  blown,    124. 
Sandstone  for  buildings,   139. 
Sapphire   for  phonographic   stylus,    153. 
Saunders  channeling  machine,  342. 
Saunders,     W.     L.,    on    introduction    air 

tools,  419. 

Saw   carriage   directly  attached,    342;   cir- 
cular, strengthened,  254;  gang,  290. 
Saws,  multiple,  290. 
Saxonville,    Mass.,    Pipe-arch    bridge,    41, 

Schmidt  superheater,  451. 

Schott,  Otto,  Jena  glass,   181. 

Schumann's    Traumerei,    333. 

Screw  as  derived  from  narwhal  tusk,  259; 
production  of,  236;  Rowland's,  237; 
propeller,  69;  with  gimlet  point,  90. 

Scroll,  free-hand,  and  development,   in. 

Sculpture,  earth,   122;   Greek,   114. 

Seamless  tubes,  46. 

Sectional  bookcases,  351. 

Sedgwick,  Adam,  fails  in  observation,  280. 

Selenium,  discovery,  properties,  conducts 
electricity  better  in  light  than  in  dark- 
ness, 394;  special  treatment,  397;  cylin- 
der of,  308. 

Self-hardening  steel,    172. 

Separation,  how  effected,   150. 

Seppings  first  uses  trusses  m  ships,  19. 

Sewing  machine  analyzed,  318. 

Sexton,  A.  Humboldt,  Metallurgy  iron 
and  steel,  178. 

Shades  for  light,  229. 

Shaper,  98,  99. 

Shearing  stresses,  6. 

Shears  for  metal  and  timber,  322. 

Shell,  Art  in,  W.  H.  Holmes,  116;  vessel 
and  clay  derivative,  115,  116;  making, 
Bliss,  184. 

Ship,  52-61;  big,  advantages,  127,  128; 
Clipper,  57;  cross-sections,  63;  design, 
judgment  in,  63;  gas  engines  for,  465; 
perforated  sails  for,  291;  resistances, 
52,  53J  studies  resistance  and  propul- 


INDEX 


501 


sion,  Carnegie  Institution,  277;  Viking, 
55.  56;   planning  ship-yard,  322. 

Shops,  small,  480. 

Shuckers,  J.    W.,  justifying  wedges,   324, 

Siemens,  Sir  William,  open  hearth  pro- 
cess, 164. 

Signals,  Westinghouse,  428. 

Silk,  artificial,  261. 

Silo,  concrete,  430,  431. 

Silt  removed  in  stream,   124. 

Silver  compounds  sensitive  to  light,    152. 

Simplification,    340-354:    undue,    383. 

Size,  120-134;  in  glass-making:  mate- 
rials should  be  pulverized,  407. 

Skill,  manual,  passes  from  ola  tasks  to 
new,  386. 

Skin  scraper,   Eskimo,  91. 

Skins  prepared  for  use,   138. 

Slags  utilized,   150. 

Slide  for  timber,  cycloidal,  341. 

Slide-rest,  94,  96. 

Smallpox  prevented  by  cowpox,  295. 

Smeaton,  James,  discovers  natural  ce- 
ment, 430. 

Smillie,  Geo.  F.  C,  acknowledgment  to, 
xxi. 

Smith,  Francis  P.,  propeller,  291. 

Smith,  Oberlin,  on  machine  design,   172. 

Smoke  abated  or  not  produced,  450;  pre- 
serves food,  137;  protects  vegetation, 
146. 

Smoke-jack,  449. 

Smokeless  powder,   Nobel's,   412. 

Smyth,  William  H.,  on  invention,  271. 

Snails,  land,  observed  by  E.  S.  Morse, 
287. 

Snake  venoms,  antidotes  for,  296;  studied 
Carnegie  Institution,  277. 

Snow,  Walter  B.,  "Steam  boiler  prac- 
tice," 45.0. 

Soap,  shaping  by  pressure,  325. 

Social  aspects  of  invention,  478. 

Sociological  observations,  Karl  Pearson 
on,  277. 

Soda  formerly  wasted  now  used.  150. 

Soil  tillage,  124. 

Solenoid,  316. 

Solid  contents  ascertained,  343,  344. 

Solids  and  surfaces,  law  of,  122. 

Sound  caused  by  light,  393.  398-400;  en- 
ables a  pneumatic  tube  to  be  cleared, 
321;  interference  of,  366;  mill,  Dvorak, 
132. 

Sparks,  electrical,  useful,  147. 

Sparrows  feeding,   136. 

Specialization,  Thomas  Young  on,  365; 
and  group  attack,  416. 

Specific  gravity  learned,  344. 

Spectacles,  bi-focal,  85. 

Spectrometer  investigates  colors  of  light, 
228. 

Spectroscope,  Frauenhofer  invents,  284; 
utilized,  218. 

Spinning,  126;  jenny,  Hargreaves  in- 
vents, 290. 

Spiral  grooves  in  fire-arms,  65;  steel 
tube,  42. 

Spring,  W.,  makes  alloys  by  pressure,  201. 

Square  root  extractor,  376,  377. 

Squirt,  garden,  371. 

Staircases,  curved  joints  for,  49. 

Stamping,   103;  machines  curved,   50. 

Standard  sizes  in  manufacturing,  239;  in 
power  plant,  385;  of  measurement 


Stars,  fixed,   observation   of,   213;   double, 

"11,    ; 


sought,  210;  electrical  measurement, 
239;  Bureau  of,  234-236,  two  varying 
yards.  195. 
ars,  fixed,  < 

measurements,  Sir  David  Gill,  286,  ob- 
served by  E.  E.  Barnard  and  S.  W. 
Burnham,  285,  286. 

Stas,  elimination  of  sodium,  364. 

Steam,  Watt's  study  of,  361;  and  gas  en- 
gines compared,  466*  engine,  automatic 
auxiliaries,  329,  condensers,  87;  Weigh- 
ton's,  452,  losses,  H.  G.  Stott,  469-71, 
performances,  448,  451,  resembles  gar- 
den squirt,  372,  multiple  cylinders,  372, 
Watt's  first,  1 01,  Allis-Chalmers,  fac- 
ing 448,  facing  452;  hammer  directly 
attached,  342;  high-pressure,  for  loco- 
motives, studied  Carnegie  Institution, 
277;  turbine,  452-456,  Westinghouse- 
Parsons,  facing  454,  costly  experi- 
ments, 414,  should  be  joined  to  steam 
engine,  H.  G.  Stott,  470;  and  both  to 
gas  engines,  471. 

Steamer  forms,  55;  for  cargo-carrying, 
59,  61. 

Steatite  fibres,  235. 

Steel,  163-179;  annealing,  168,  J.  V. 
Woodworth,  179;  barrel  pressed,  185; 
Bessemer's  story  of  his  process,  403- 
407:  corrodibility  reduced,  167;  crys- 
tallization, J.  W.  Mellor,  178;  dies, 
175,  effects  of  use,  358;  drills,  418; 
electric  and  magnetic  qualities,  151; 
examined  microscopically,  163;  ex- 
panded, 437,  438;  for  biggest  struc- 
tures, 128;  for  mechanical  night,  129; 
forging,  J.  V.  Woodworth,  179;  hard- 
ening, J.  V.  Woodworth,  179;  heat 
treatment,  167,  study  aided  by  Carne- 
gie Institution,  277;  high-speed  tool, 
171;  in  architecture,  119;  invar,  169; 
iron  and  other  alloys,  H.  M.  Howe. 
177;  manganese,  non-magnetic  and 
tough,  171;  manufacture  of,  H.  H. 
Campbell,  177:  manufacture  iron  and, 
Sir  I.  L.  Bell,  177;  mechanical  treat- 
ment, F.  W.  Hall  (See  under  Har- 
bord),  177;  Metallurgy,  F.  W.  Har- 
bord,  H.  M.  Howe,  177,  A.  H.  Sex- 
ton, 178,  T.  Turner,  179;  pressed,  car, 
186;  rails,  169,  wear  at  Crewe,  406; 
range  pressed,  185,  186;  rolls,  104; 
strength  of,  20,  J.  Hopkinson  on,  384; 
tempering,  168,  J.  V.  Woodworth  on, 
170;  to  order,  166;  tube,  spiral,  42; 
tubing,  uses  for,  40,  41;  under  micro- 
scope, facing,  164;  J.  W.  Mellor,  178; 
used  unduly  thick,  117;  wire,  strength, 
32;  works  directory,  J.  M.  Swank, 
178. 

Stemheil's  ground  wire  in  telegraphy, 
346. 

Stephenson,  George,  as  a  mechanic,  299; 
railroad  lines,  246. 

Stewart,   Balfour,  on  meteorology,   338. 

Stoker,  automatic,  330,  450;  underfeed, 
380. 

Stolp  radiator,  87. 

Stone  outlines,  112;  as  chosen  by  In- 
dians, 143;  broken  by  frost,  123. 

Stop  motion,  330. 

Storage  cell,  Edison,  374. 

Stott,  Henry  G.,  acknowledgment  to,  xxi; 

on  power  plant  economies,  469-71. 
Stoughton,    Bradley,    acknowledgment   to. 


502 


INDEX 


173;  list  of  books  on  iron  and  steel 
chosen  and  annotated  by,  176. 

Stoves  for  heating,  86;  Canadian  box 
and  dumb,  86. 

Strains  in  bridges  studied,  25;  revealed 
by  polarized  light,  327. 

Strap  rail  and  stringer,   13. 

Stream,   model,   by  James   Thomson,   283. 

Stresses  tested,    192;   recurrent,    191. 

Strowger,  Almon,  inventor  automatic  tel- 
ephone, 337. 

Strut  of  bridge,  23. 

Sturgis,  Russell,  on  modern  architecture, 
119. 

Sturtevant  ventilating  and  heating  ap- 
paratus, 380,  472. 

Sugar,  polarized  light  measures,  327. 

Sugar-cane  mill,   Bessemer's,  402. 

Sulky  in  steel  tubing,  41. 

Sulphate  of  ammonia  from  Mond  plant, 
461. 

Sun,  size  of,  121. 

Sundew  traps  insects,  281. 

Superheaters,  450,  451. 

Surfaces  and  solids,  law  of,   122. 

Surveying,  invar  wires  for,  170. 

Suspension  bridges,  32;  wnere  best,  35. 

Swallow,  bank,  lesson  from,  297. 

Swank,  J.  M.,  Directory  Iron  and  steel 
works;  History  manufacture  iron,  178. 

Tainter,  Sumner,  aids  Professor  A.  G. 
Bell  in  perfecting  photophone,  393. 

Talking  Machine,  Faber,   343. 

Tamarac  copper  mine,   stamp,  344,  345. 

Tamping,   compressed   air  for,   420. 

Tanks,  experimental,  for  ship  models,  54, 
55;  U.  S.  Navy,  facing  54;  reinforced 
concrete,  441. 

Tantalum   electric  lamp,    159,    160. 

Taylor  gas  producer,  460. 

Team  work  in  research  and  invention, 
415- 

Telautograph,   Gray,   313,  facing  318. 

Telegraphic  registers,    Edison's,    310. 

Telegraphone,   Poulsen,    313,   facing  314. 

Telegraphy,  ground  wire  in,  346;  codes 
m»  352-354. 

Telephone,  Professor  Bell's  narrative  of 
invention,  393,  foot-note;  earnings,  484; 
as  part  of  photophone,  395;  two  con- 
ductors for,  149;  automatic,  335-337; 
central  station,  257;  researches,  M.  I. 
Pupin,  367-369. 

Telescope,  aid  from,  356;  air  churned  in, 
348. 

Tellurium  added  to  bismuth,  175. 

Tempering  steel,   168. 

Tension,  8;  members  need  not  be  of 
rigid  material,  19. 

Terra  cotta,  323. 

Testing  apparatus,  Emery,  242;  Laborato- 
ries, Electrical,  N.  Y.,  242;  materials, 
American  Society  for;  International 
Association  for,  241 ;  industrial,  in- 
creasing in  demand,  243. 

Thacher,  Edwin,  bar,  436;  on  reinforced 
concrete  bridges,  436,  444. 

Thawing  ice  by  electric  heat,  347. 

Theater,  New  Amsterdam,  New  York, 
119,  facing  1 1 8. 

Theories,  how  reached  and  used,  355-386. 

Thermo-electricity  and  its  converse,  373. 

Thermometer,  mercury,  225;  Jena  glass 
for,  182. 


Thermometry,  interferometer  in,  216. 

Thomas,   Carl   C.,   "Steam  turbines,"  456. 

Thomas,  J.  J.,  "Farm  Implements" 
quoted,  340. 

Thompson,  Benjamin,  founds  Royal  Insti- 
tution, 365;  proves  heat  to  be  motion, 
206. 

Thomson,  James,  models  stream,  283. 

Thomson,  Joseph  J.,  on  electrons,  132; 
on  cathode  rays,  198. 

Thorium  radio-active,  199;  Ernest  Ruth- 
erford's researches  in,  200;  two  sub- 
stances separated  from,  by  Charles 
Baskerville,  200;  in  gas  mantle,  156, 
157- 

Through  bridge,  24. 

Thurston,  R.  H.,  on  inventors  of  the 
past,  265;  on  planning  investigation, 
270. 

Tie  of  railroad,   13;  bridge,  23. 

Tiffany,  George  S.,  improves  telauto- 
graph, 317. 

Tiles,  roofing,  studied  by  E.  S.  Morse, 
288. 

Tilghman,  B.  C.,  sandblast,  124,  424. 

Tillage  soil,   124. 

Timber,  Murphy  machine  shears,  327; 
slide,  cycloidal,  341. 

Time  modifies  properties,  138;  measure- 
ment, 221,  222;  service,  W.  U.  Tele- 
graph Co.,  330. 

Tool  design,  89;  materials  for,  136;  ma- 
chine, 94-101. 

Tooth  of  beaver,  258. 

Torpedo-boat  destroyer,  62,  64. 

Total   reflection,   76-82. 

Towers,  Beauchamp,  researches  on  fric- 
tion, 274. 

Track  indicator,  Dudley's,  14. 

Trade,  how  it  began,   219. 

Training,  manual,  309,  310. 

Transmission   motive  power,    347. 

Traumerei,  Schumann  s,  333. 

Tray,  wooden,  and  clay  derivative,  115, 
116. 

Triangle  as  stable  form,   18,   19. 

Triggers,  chemical,  337. 

Truss,  model  of  simple,  19;  Baltimore, 
25;  Howe,  24,  25;  kingpost,  18;  Pratt, 
24,  25;  queen-post,  21;  Palladio,  22. 

Tubes,  Mannesmann,  46;  for*  radiators, 
87. 

Tungsten  in  high-speed  tool  steel,  172; 
electric  lamp,  160. 

Tunnel,  bank  swallow  gives  hint  for,  297; 
bored  through  frozen  ground,  326;  con- 
crete, 430. 

Turbine  wheels,  69,  70;  Francis  vertical, 
446;  reversed  as  pump,  371;  supported 
by  upward  pressure  water,  371;  steam, 
reversed  as  air  compressor,  372.  (Fo^ 
other  entries  see  under  Steam-turbine.) 

Turner,  Thomas,  Metallurgy  iron  and 
steel,  179. 

Turret  lathe,  97. 

Twist  drills,  93. 

Tyndall,  John,  on  dogmatism,  363;  on 
imagination,  361 ;  on  original  research, 
273;  on  scientific  co-operation,  274; 
on  verification,  362. 

IT-bend  in  pipe,  88. 

Ultra-violet  rays,  Jena  glass  utilizes,    182. 
Umstead,     C.     H..     strengthens    concrete 
with  crushed  stone,  240. 


INDEX 


503 


Uniform  voltage  economizes  lighting  cur- 
rent, 243. 

Unit  systems,  350,  351. 

United  States  Geological  Survey,  coal 
testing  plant,  241,  foot-note;  Steel  Co., 
as  carriers,  415. 

Unity  of  nature,  357. 

Uranium,  radio-active,  199. 

Use  creates  beauty,  104,  105. 

Uviol  lamps,  183. 

Vacuum,     James    Dewar    produces,     327; 

cleaning  method,  423,   facing   156. 
Valve-motion,    Humphrey   Potter's,   329. 
Valves  of  veins,  251.  252. 
Van  Vleck,  John,  acknowledgment  to,  xxi. 
Variations  seized,  249. 
Vase  from  tumulus,  116. 
Vegetation,      engineering      principles      in, 

247;  smoke  protects,  146. 
Vehicles,   forms,   65. 
Veneer  as  wall  covering,  342. 
Ventilating      and       heating,       Sturtevant 

methods,   380,   472. 
Verification,  Tyndall,  362. 
Vial  and  bubbles.   127,    128. 
Victoria  Bridge,  Montreal,  26-28. 
"Victorian"  driven  by  steam  turbines,  455. 
Viking  ship,   <>5,   56. 
Vines  saved  from  phylloxera,  289. 
Violet,  zinc,  296. 
Violins  improve  with  use,   192. 
Volcanic  outbreaks,  245;  Krakatoa,  125. 
Voltmeter,  Weston's,  232. 
Volutes  in  turbines,  69. 
Vulcanite  somewhat  transparent,  338. 

Wachusett  Dam,  concrete,  431. 

Wadsworth,  F.  L.  O.,  improves  inter- 
ferometer, 217. 

Wage-earners,  more  in  manufacturing 
than  formerly,  479. 

Wages,  premiums  In,  244;  American, 
average  in  1900,  486. 

Waidner,  Dr.,   Bureau  of  Standards,   235. 

Wallace,  A.  R.,  facts  and  arguments, 
359-. 

Warship  curves,    51. 

Wasp  nest  suggests  paper  from  wood, 
261;  using  peoble  as  hammer,  260. 

Wastes  prevented,   149. 

Watches  and  watch-making  machines,  222. 

Water,  angle  total  reflection,  77,  78; 
boiling  point  lowered  as  atmospheric 
pressure  lessens,  375;  courses  deep- 
ened, 123;  current,  two  modes  of 
measuring,  370;  expands  in  freezing, 
pressure  lowers  freezing  point,  375; 
gas,  459;  moving,  as  source  of  power, 
360;  pipes  gradually  joined,  50,  rein- 
forced concrete,  442;  supply  indicated 
by  Tegetation,  297;  tight  basketry,  142, 
143;.  under  pressure  for  power  trans- 
mission, 348. 

Watson,  Egbert  P.,  suggests  steel  tubing 
for  bridges,  41,  42. 

Watt,  James,  a  mechanic  from  boyhood, 
299,  302;  articulated  water-pipe,  258; 
study  of  steam,  361;  first  steam  en- 
gines, 101;  on  omissions,  346;  suggests 
metric  system,  211. 

Wax.  shoemaker's,  is  plastic,  195. 

Weapons,  materials  for,  136. 

Weather  predictions,  338,  330. 

Weaving,   its   beginnings,    138;    materials, 


Wedge  extracts  square  root,  376-77;  jus- 
tifying, 323-25;  front  automobile,  66. 

Weighton,   R.  L.,  steam  condensers,  452. 

Welsbach,  Dr.  Auer  von,  portrait,  facing 
156;  gas  mantle,  155-59,  and  Holo- 
phane  globe,  81;  osmium  electric  lamp, 
1 60. 

Western  Union  Telegraph  Co.,  time  ser- 
vice, 330. 

Westinghouse  brakes  and  signals.  428. 

Weston  ammeter,  233;  voltmeter,  232; 
factory,  234,  foot-note. 

Wheel,  balance,  in  time-pieces,  222; 
Earnshaw's  compensated,  223;  bicycle, 
382;  carborundum,  101,  102-  emery, 
101,  102;  flange  on,  instead  of  on 
track,  370;  Pelton,  71;  spokeless,  66; 
toothed,  67. 

Whetham.  W.  C.  D.,  "Recent  Develop- 
ment of  Physical  Science,"  204. 

Whipple  bridge,  25. 

White,  J.  G.  &  Co.,  effect  economies, 
244. 

White  ware,  origin,  290. 

Whitney,   Eli,  interchangeability,  239. 

Williamsburg  suspension  bridge,  32,  33. 

Wind,  work  of,   124. 

Windmill  vanes,  70;  and  fan  blower,  371. 

Wire  fabric,  lock-woven,  430;  shaped  by 
hydraulic  pressure,  326;  shortened,  81; 
tempered  as  drawn,  343. 

Wollaston,  observes  black  lines  in  spec- 
tra, 284;  on  threshold  of  photography, 
284. 

Wolvin,  Augustin   B.,  ore  carrier,  69. 

Woman's  share  in  primitive  culture,  O. 
T.  Mason,  107. 

Wood,  strength  of,  21;  compressed,  152; 
borer,  compressed  air  for,  420. 

Wood,  Dr.   Casey  A.,  on   diseases  of  the 

eye.  379. 

Wood,  R.  D.  &  Co.,  gas  producer,  460,  466. 

Wooden  tray  and  clay  derivative,  115, 
116. 

Woodward,  C.  M.,  on  manual  training, 
309,  310. 

Woodward,  R.  S.,  Carnegie  Institution 
for  Original  Research,  276;  portrait, 
facing  276. 

Wood-work,   Japanese,   113. 

Wpodworth,  J.  V.,  Hardening,  temper- 
ing, annealing  and  forging  steel,  179; 
on  milling  cutters,  377. 

Work  from  fuel  in  human  body,  263, 
264.. 

Worthington  pump,  70. 

Wrappings  of  merchandise,  129. 

Writing  appliances,    114. 

Wyer,  Samuel  S.,  Producer-gas  and  gas- 
producers,  462. 

Xenon,   213. 

X-rays  examine  electric  cables,  327; 
make  air  electric  conductor,  282. 

Vokut  basket  bowl.   112. 
Young  America,  clipper  ship,  £7,  58. 
Young,     Thomas,     discovers    interference 
light,  366;  on  discursiveness,  365. 

Zahm,  A.   F..  mechanical  flight,  262. 
Zeiss  binocular  glasses,  81,  82. 
7inc  violet,   296. 
Zirconium  for  gas  mantle,   156. 
Zuni  water  vessels,  108. 


FLAME,  ELECTRICITY  AND 
THE  CAMERA 

BY  GEORGE  ILES 

A  CONCISE  and  brilliant  recital  of  the  chief  uses  of  fire,  elec- 
tricity and  photography.  The  steam  turbine,  the  production  of 
utmost  cold,  the  Rontgen  ray  apparatus,  the  revelations  of  the 
sensitive  plate  directed  to  the  sky,  color  photography,  the  wire- 
less telegraph,  are  among  the  inventions  depicted  and  explained. 

The  original  points  in  the  book  are : 

Proof  that  ELECTRICITY  can  do  all  that  FIRE  does,  do  it  better, 
and  then  accomplish  uncounted  tasks  impossible  to  flame. 

PHOTOGRAPHY  is  shown  to  be  the  one  radical  advance  in  de- 
piction since  art  began.  In  days  of  old  an  object  had  to  be  seen 
before  it  could  be  pictured ;  to-day  new  heavens  and  a  new  earth 
impress  their  images  first  in  the  camera,  to  declare  themselves 
only  afterward  to  the  eye. 

Heretofore  EVOLUTION  has  been  explained  by  mere  excellence 
in  swiftness,  strength,  vision.  This  book  points  out  how  the  abil- 
ity to  change  the  forms  of  things  flowered  into  the  capacity  to 
change  their  properties  as  well.  When  an  arrowmaker  in  strik- 
ing flint  against  flint  kindled  flame,  and  repeated  the  feat  at  will, 
he  opened  at  once  a  new  world  for  humankind,  incomparably 
higher  and  broader  than  if  he  had  simply  acquired  a  nicer  touch, 
a  steadier  aim,  a  quicker  ear  for  the  rustle  of  leaf  or  wing.  It 
is  the  like  maturing  of  old  resources  into  new,  of  infinitely  greater 
scope,  that  has  brought  man  to  the  supremacy  of  Nature,  while 
his  next  of  kin  remain  beasts  of  the  glade. 

Fully  illustrated  and  with  frontispiece  in  colors,  $2. 

DOUBLEDAY,  PAGE  &  CO., 

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